Lateral Section Research Articles

Central Liver Segments Resections vs Extended Hepatectomies in Children: Single-center Experience

BackgroundCentral liver segments resection (CLSR) still is not widely used in pediatric surgery due to its technical difficulty, whereas this procedure is widely spread as a parenchyma sparing approach of centrally located liver tumors in adults. The aim of this study is to analyze the outcomes of CLSR in comparison with extended hepatectomy (EH) in children with different liver tumors. MethodsA single-center retrospective analysis of patients who received CLSR (n = 14) and EH (n = 44) from June 2017 to December 2023 was applied. Patient's characteristics, preoperative, intra- and postoperative data were compared between 2 groups. ResultsPreoperative CT-volumetry showed that future liver remnant volume was higher in CLSR group compared to EH (FLR-V; (54 ± 29 (40–91) % vs 40 ± 12 (17–73) %, p = 0.016). The intraoperative blood loss (200 [90–1150] (20–3000) ml vs 100 [30–275] (10–9000) ml, p = 0.088) and transfusion volume (310 [85–590] (0–1860) ml vs 150 [0–310] (0–4770) ml, p = 0.484) were similar in both groups, while operation time was longer in CLSR group (420 [320–595] (145–785) min vs 280 [203–390] (125–710) min), p = 0.011). There was no difference in biliary leakage (3 (21.4 %) vs 12 (27.3 %); p = 0.479), other complications (4 (28.6 %) vs 5 (11.4 %), p = 0.198) and complications ≥ IIIb by Clavien-Dindo (2 (14.3 %) vs 8 (18.2 %), p = 0.385) postoperatively. ConclusionCLSRs allow to preserve more healthy liver parenchyma compared to EH with similar intraoperative and postoperative outcomes. «Extended mesohepatectomy» allows to achieve R0 resection when central liver tumor extends on the left lateral and/or right posterior section. Type of StudyRetrospective Comparative Study (Level of Evidence III).

Bite hard: Linking cranial loading mechanics to ecological differences in gnawing behavior in caviomorph rodents.

The mammalian skull is very malleable and has notably radiated into highly diverse morphologies, fulfilling a broad range of functional needs. Although gnawing is relatively common in mammals, this behavior and its associated morphology are diagnostic features for rodents. These animals possess a very versatile and highly mechanically advantageous masticatory apparatus, which, for instance, allowed caviomorph rodents to colonize South America during the Mid-Eocene and successfully radiate in over 200 extant species throughout most continental niches. Previous work has shown that differences in bite force within caviomorphs could be better explained by changes in muscle development than in mechanical advantages (i.e., in cranial overall morphology). Considering the strong bites they apply, it is interesting to assess how the reaction forces upon the incisors (compression) and the powerful adductor musculature pulling (tension) mechanically affect the cranium, especially between species with different ecologies (e.g., chisel-tooth digging). Thus, we ran finite element analyses upon crania of the subterranean Talas' tuco-tuco Ctenomys talarum, the semi-fossorial common degu Octodon degus, and the saxicolous long-tailed chinchilla Chinchilla lanigera to simulate: (A) invivo biting in all species, and (B) rescaled muscle forces in non-ctenomyid rodents to match those of the tuco-tuco. Results show that the stress patterns correlate with the mechanical demands of distinctive ecologies, on invivo-based simulations, with the subterranean tuco-tuco being the most stressed species. In contrast, when standardizing all three species (rescaled models), non-ctenomyid models exhibited a several-fold increase in stress, in both magnitude and affected areas. Detailed observations evidenced that this increase in stress was higher in lateral sections of the snout and, mainly, the zygomatic arch; between approximately 2.5-3.5 times in the common degu and 4.0-5.0 times in the long-tailed chinchilla. Yet, neither species, module, nor simulation condition presented load factor levels that would imply structural failure by strong, incidental biting. Our results let us conclude that caviomorphs have a high baseline for mechanical strength of the cranium because of the inheritance of a very robust "rodent" model, while interspecific differences are associated with particular masticatory habits and the concomitant level of development of the adductor musculature. Especially, the masseteric and zygomaticomandibular muscles contribute to >80% of the bite force, and therefore, their contraction is responsible for the highest strains upon their origin sites, that is, the zygomatic arch and the snout. Thus, the robust crania of the subterranean and highly aggressive tuco-tucos allow them to withstand much stronger forces than degus or chinchillas, such as the ones produced by their hypertrophied jaw adductor muscles or imparted by the soil reaction.

Stress-strain state of prosthetic structures on implants during replacement of a dentition defect

Material and methods. Under the conditions of a three-dimensional mathematical model of the lateral section of the lower jaw with three missing teeth, the stress-strain state of the defect replacement options was studied: three implants with covering crowns, a bridge prosthesis supported by two implants, a bridge prosthesis supported by a tooth and an implant. A load of 150 N was applied to the middle of the prosthetic structure in the vertical and inclined directions; the maximum stress values and their distribution were compared. The results of the study. The negative effect of the inclined load on the magnitude and distribution of stresses was confirmed (471.7 MPa versus 90.7 MPa with vertical load on the example of three implants), the most loaded zones of prosthetic structures were identified – the edge of the artificial crown and the implant junction zone. A uniform distribution of stresses from the bridge prosthesis to 2 support implants and a decrease in stress values were found when replacing the structure of three implants with crowns with a bridge prosthesis (16.1 MPa and 160.0 MPa). On the contrary, the overload of the support implant was recorded when replacing the second support implant with a tooth (1053.5 MPa with an inclined load). Conclusion. In comparison with three implants replacing a dentition defect due to the absence of three teeth, a bridge prosthesis supported by two implants reduces stresses in the implants and the covering structure. Replacing one support implant with a tooth increases the stresses in the structure on the implant to the strength limits of the titanium alloy in the abutment.

Quantitative analysis of sagittal curvatures of the tibial plafond by computed tomography.

Although the talar morphology has been well understood, studies on the corresponding tibial plafond are still lacking. Based on computed tomography (CT) data, this quantitative study divided the tibial plafond into anterior and posterior regions on five sagittal sections. The objectives of this study were (I) to determine whether the sagittal curvatures of the tibial plafond can be quantitatively and accurately described using the double-diameter method; (II) to compare the difference between the anterior and posterior diameters on five sagittal sections. In this study, CT data were collected from 100 adult ankles, and the three-dimensional (3D) ankle joint model was reconstructed using CT images. An anatomical coordinate system of the 3D ankle joint model was created to establish the standard coronal and sagittal planes. The measurement outcomes of sagittal curvatures included: the anterior and posterior diameters, the distal tibial arc length (TiAL) and the distal tibial mortise depth (TMD) on five sagittal sections (the most medial, medial 1/4, middle, lateral 1/4 and the most lateral section). Subgroup analysis was performed to compare the differences between males and females. Analysis of the sagittal curvatures showed that the anterior diameter of tibial plafond was significantly smaller than the posterior diameter on five sagittal sections with a mean difference ranging from 3.9 to 6.8 mm (P<0.001). For the anterior diameters, the anteromedial curve had the smallest diameter (35.3±5.3 mm), and the anterolateral curve had the largest diameter (38.0±5.8 mm). For the posterior diameter, the posteromedial curve had the smallest diameter (39.2±6.4 mm), and the posterolateral 1/4 curve had the largest diameter (43.5±6.9 mm). One-way analysis of variance (ANOVA) revealed significant differences in the anterior and posterior diameters among five groups (P<0.012). Subgroup analysis showed that gender partly affected the results of sagittal curvature measurements. The sagittal curvatures of the tibial plafond can be described quantitatively and accurately using anterior and posterior diameters. Our study showed that there were significant differences between the anterior and posterior diameters, and gender was an important factor influencing the sagittal curvatures of the tibial plafond.

3D-printed Ti6Al4V thoracic fusion cage: Biomechanical behavior and strengthening mechanism

To effectively replace diseased and damaged thoracic vertebrae, a series of three-dimensional (3D) printed titanium (Ti) alloy (Ti6Al4V) thoracic fusion cages with varying volume ratio of reinforced scaffolds are designed, and their structure-function relationships are investigated systematically. It is demonstrated that the mechanical strength of fusion cage is gradually enhanced as the scaffold volume increases, which may be attributed to its textural transformation from α phase to β phase. The compressive, shear, and fatigue of fusion cages successfully attain the International Organization for Standardization (ISO 23089), when the scaffold volume ratio exceeds 15%. Furthermore, the biomechanical analyses, including stress distributions and subsidence in flexion, extension, axial rotation, and lateral bending sections of fusion cages, further shed light on their potential clinical applications. This work deeply deciphers the intrinsic connection between biomechanical property and material texture of the thoracic fusion cages, offering valuable insights into their strengthening mechanism, which providing a guidance for the precise design and quick synthesis of other 3D-printed Ti6Al4V implants.

Investigating the Effects of Cargo Weight and its Distribution on the Dynamic Performance of a High-Speed Planing Hull

The aim of this article is to evaluate the effects of cargo relative weight and its distribution along the boat’s length in addition to the relative water wavelength on the dynamic performance of a high-speed planing hull. Here, the dynamic performance is measured by the intensity of the boat’s heave and pitch motions. The Zarnick’s strip theory, which divides the vessel’s hull into equal lateral sections, is used to study the applied forces on the vessel, and a MATLAB code is provided based on it. It is demonstrated that increasing the cargo weight and its distribution result in more heave and pitch, and the maximum amount of them are observed in the wave with a length of about 5 times the length of the boat. In addition, the interactive effects of cargo weight and its distribution on the heave and pitch motions are affected by the relative wavelength. Therefore, the more centralized cargo distribution is preferred to increase the dynamic performance of a heavy planing boat with cargo weights more than 50% of the boat’s weight, while moving in short waves (λ⁄L&amp;lt;4); and for light cargo weight, less than 50% of the boat’s weight, the favorite cargo distribution is broad. When the boat sails in long waves, the desired distribution is reversed.

The influence of oral breathing type on the formation of occlusion in students of general educational institutions of the Ministry of Defense of Russian Federation

BACKGROUND: Among students of general education organizations of the Ministry of Defense of Russian Federation, respiratory diseases is the leading cause of general somatic morbidity and amount to 1543.5‰. When examining students, pathology of the upper respiratory tract is often diagnosed, such as partial or complete obstruction of the nasopharynx and/or oropharynx. Against this background, the formation of the oral type of breathing occurs, which affects the state of general somatic health and growth and development of the facial skeleton. AIM: To evaluate the influence of oral breathing on the dentoalveolar and gnathic parameters of the maxillofacial region in students of educational institutions of the Ministry of Defense of Russian Federation. MATERIALS AND METHODS: This study examined two groups of students aged 13–15 years from the St. Petersburg Cadet Military Corps named after Prince Alexander Nevsky: group 1, 30 cadets with oral breathing, and group 2 (control), 30 cadets with nasal breathing. All patients underwent an examination of the oral cavity, a photo protocol, scanning of the dentition, and cone-beam computed tomography of the skull bones and first cervical vertebrae in natural occlusion with a resolution of 17×15. The data were checked for normal distribution of features. The article presents arithmetic averages and their errors (M±m). RESULTS: All the examined group 1 students with oral breathing were diagnosed with distal bite in combination with other dental anomalies: combined anomalies in the form of distal bite and disocclusion in the frontal region (56.7%); close position of the anterior group of teeth (93.3%); and unilateral (30.0%) and bilateral (13.3%) cross occlusion due to narrowing of the upper and lower jaws. In most cases, the group 1 students were diagnosed with a gnathic form of dentoalveolar anomaly (ANB parameter, 6.6±2.4°; Beta parameter, 24.7±3.1°) against the background of retroposition of the lower jaw (SNB parameter, 75.4±2.8°) and a decrease in the length of the lower jaw (Co–Gn parameter, 106.0±2.8 mm). All the group 2 (control) students had a neutral occlusion with a normal position of the upper jaw (SNA parameter, 81.4±2.1°) and a normal position of the lower jaw (SNB parameter, 79.8±1.6°) and the first skeletal class (ANB parameter, 2.3±1.1°; Beta parameter, 30.1±2.5°). CONCLUSION: Oral breathing is accompanied by the development of disto-occlusion with the formation of a vertical gap in combination with cross occlusion in the lateral sections and close position of the anterior group of teeth against the background of a narrowing of the upper and lower jaws. Prompt diagnosis of upper respiratory tract pathology prevents the development of dentoalveolar and gnathic disorders of the maxillofacial area. To treat patients with oral breathing, a simultaneous approach is required with the involvement of a full-time otolaryngologist at the medical center.

The effect of a barrier membrane on the incorporation of deproteinized bovine bone mineral (DBBM) in experimental defects at the time of early implant placement. A preclinical study

ObjectivesThis study aimed to assess membrane use with a bone substitute graft for guided bone regeneration (GBR) in experimental dehiscence defects.Materials and methodsMaxillary second incisors (I2) in 9 dogs were extracted. Six weeks later, implants were inserted and experimental dehiscence defects (5 × 3 mm) created on the buccal aspect. The defects and surrounding bone were grafted with deproteinized bovine bone mineral. One side (test) was covered with a resorbable collagen membrane whereas the contralateral side (control) was not. After 6 weeks, histomorphometrical analysis was performed to evaluate: (a) first bone-to-implant contact (fBIC), (b) buccal bone thickness at 1 mm increments from implant shoulder, (c) regenerated area (RA), (d) area and percentages of new bone (B), bone substitute (BS) and mineralized tissue (MT).ResultsThe histological appearance was similar between test and control sites. At central and lateral sections, there were no differences between groups for fBIC, buccal bone thickness, RA, BS, B, %B, MT and %MT. At central sections, membrane use favoured more %BS and %MT (p = 0.052). There was significantly more B, %B and MT at lateral compared to central sections.ConclusionsMembrane use tended to retain more bone substitute, but had no effect on new bone ingrowth. Lateral sections showed significantly more bone ingrowth and mineralized tissue compared to central sections, confirming that new bone ingrowth takes place mainly from the lateral walls of the defect.Clinical relevancePreclinical research to clarify the dynamics of bone regeneration in GBR procedures is relevant in clinical practice.

Development and simulation of the gas-downhole water sink-assisted gravity drainage (GDWS-AGD) process to reduce carbon footprint and improve clean oil production by injecting CO2 and petroleum-associated gas

Implementing continuous gas injection into oil reservoirs, surrounded by strong water drives, enhances oil production. Nevertheless, water coning/cresting in these reservoirs leads to high water cuts, substantial oil production reductions, and major water-handling issues for surface facilities. The Gas-Downhole Water-Sink-Assisted Gravity Drainage (GDWS-AGD) process can enhance oil recovery (EOR) in such reservoirs and mitigate the influx of aquifer water into the oil zone. This study compares the performance of GDWS-AGD and GAGD processes based on reservoir-simulation results for two heterogeneous reservoirs: the PUNQ-S3 reservoir and the giant South Rumaila (SR) oil field (Iraq).The PUNQ-S3 simulation exclusively employs carbon dioxide (CO2) as the injected gas. In contrast, the SR simulation evaluates the CO2 injection in comparison to petroleum-associated gas (PAG). The GDWS-AGD process performance was assessed based on oil recovery factor, water cut, gas-to-oil ratio (GOR) in oil producers, cumulative volumes of gas injected, and oil/gas saturations. The PUNQ-S3 simulation employs six wells: two vertical CO2 injectors with perforations at the top of the reservoir to form a gas-cap zone. Additionally, there are two horizontal oil-production wells and two horizontal water-production wells positioned below the oil-water contact (OWC). The GDWS-AGD process was assessed in the SR simulation, using CO2 and PAG, in several configurations to compare it with the basic GAGD. In the SR design, twenty-two vertical gas-injection wells, ten horizontal oil-production wells, and six horizontal water-production wells were placed in the gas-, oil-, and water-bearing zones, respectively. A vertical well was dual-completed with two lateral sections originating from separate kick-off points above and underneath the OWC with 2–3/8-inch tubing for oil and water production, respectively. Hydraulic packers in the vertical wellbore separate oil and water production tubing in the dual-completion configuration, and electric-submersible pumps are then employed for water production.The downhole-water-sink configuration effectively reduces oil-reservoir pressure and minimizes water cut/cresting tendencies. CO2 remains immiscible due to reduced gas-injection pressure and decreased solubility. The CO2-based simulation of the SR field yielded oil-recovery factors of 71.67%, 75.25%, and 76.162% for the GAGD, basic, and advanced GDWS-AGD setups, respectively. The oil-recovery factor of GDWS-AGD was further increased to 82.64% by implementing PAG injection, resulting in a decrease in water cut to 5% in all oil producers. Although PAG gas injection outperforms CO2 in oil recovery, water cut, and gas injectivity in the SR field simulation, the GDWS-AGD approach with CO2 remains a feasible option. This technology has the capability to effectively capture and store significant amounts of CO2 in the flooded reservoir for many years, thereby mitigating carbon emissions associated with fossil fuel usage.

Lateral electrical conductivity variations along the Main Himalayan thrust in the northwestern Himalayas: Insights from 3D Magnetotelluric forward modeling

Understanding the arc parallel variation on the geometry of the Main Himalayan Thrust (MHT) is as important as understanding the arc perpendicular variation in the Himalayas. The geometric variability of the MHT holds significant implications for the occurrence of major and great earthquakes. Three-dimensional magnetotelluric (MT) forward modeling enables the investigation of potential crustal models along the MHT in northwest Himalayas. MT impedance tensors were computed utilizing the 3D forward modeling code MTD3FWD. Previously established MT resistivity and seismic velocity models from various sectors of the northwestern Himalayas were employed as inputs for generating the resistivity mesh necessary for 3D forward modeling. The computed impedance tensors by 3D forward computation were cross-referenced with the original published MT data to validate their accuracy. A lateral resistivity cross section is also derived from the 3D forward model along the sub-Himalaya and lesser-Himalaya region to study the lateral heterogeneity. The lateral resistivity cross-section reveals significant heterogeneity within the crust, marked by both high and low-resistive structures and a possible lateral ramp along the MHT. The geometry of the lateral MHT showcases a gradual incline within the Himachal sector and a steep ramp within the Garhwal and Kumaun sectors in the northwestern Himalayas. The crustal architecture exhibits distinct nearly-vertical resistive and conductive features beneath the study area. Consequently, the crust within this region is characterized by considerable heterogeneity, influenced by a network of subsurface faults and ridges. The Delhi Haridwar Ridge, which exhibits high resistivity, plays a significant role in dictating the lateral dip of the MHT and exerting control over seismic activity patterns in the region.

The use of an innovative technique for perforations of the mucous membrane of the maxillary sinus during the sinus lift operation

Introduction. To date, according to WHO, the number of people with a complete absence of teeth is greater than 8% of all the people worldwide. Loss of teeth due to complications of caries treatment, chronic periodontitis and trauma leads to atrophy of the alveolar ridge and that of soft tissues in this area, which in turn complicates the rehabilitation of the patients. According to the literature, in the first year after tooth extraction, the volume of the bone tissue of the alveolar ridge decreases by 40–60%, which greatly complicates the subsequent orthopedic rehabilitation of the patients. Currently, the «gold standard» for increasing the volume of the bone tissue of the alveolar ridge of the upper jaw in the distal section is the sinus lift operation. However, according to the literature, when sinus lift operation is performed, Schneider’s membrane perforation occurs in 7–23% of cases, which in terms, leads to the inability to complete the operation and complications in cases with total perforations of membrane.Purpose of the study. To evaluate the complex rehabilitation of patients with partial secondary absence of teeth and severe atrophy in the lateral sections of upper jaw using the «envelope technique» during open sinus lifting.Materials and methods. In 2020–2022, during a clinical study at the clinic of the Department of maxillofacial and plastic surgery of the Moscow State Medical University named after A.I. Evdokimov, 54 patients who had a history of PPI interventions in the ENT department were treated. All patients underwent bilateral open sinus lifting using enamel matrix proteins or the «envelope technique» for perforation of the Schneider membrane. After 9–12 months, a comprehensive rehabilitation of patients based on dental implants was carried out.Results. The number of extensive (total) perforations of the Schneider membrane in the study group of patients was 50%. As a result of the use of the patented «envelope technique» with the use of enamel matrix proteins, no postoperative complications were observed in patients with total perforation of the Schneider membrane. Taking into account the planned orthopedic design, 292 dental implants were installed in all patients.Conclusion. The method is effective and safe, allowing to rehabilitate patients with missing teeth and severe atrophy in the lateral part of the upper jaw, in case of intraoperative total perforation of the Schneiderian membrane.

A rare complication of pediatric liver transplantation: Post-transplant diaphragmatic hernia.

Acquired post-transplant diaphragmatic hernia (PTDH) is a rare complication of liver transplantation (LT) in children. We aimed to present our experience in PTDH, and a possible causative background is discussed. Medical records of patients who had undergone diaphragmatic repair following LT between 2015 and 2023 were reviewed. Demographic information, details of primary diseases necessitating LT, transplantation techniques, and clinical findings associated with PTDH were evaluated. There were seven patients with PTDH. Median age at transplantation was 69 (range: 9-200) months. Five patients received a left lateral sector, one patient had a right lobe, and one had a left lobe graft. Time between LT and PTDH was 9 (2-123) months. One patient who was diagnosed in the postoperative 10th year was asymptomatic. Respiratory distress and abdominal pain were the main symptoms among all. All patients underwent laparotomy, and primary repair was performed in six patients, and one patient required mesh repair because of a large defect. Small intestine herniated in most cases. There were two complicated cases with perforation of the stomach and colonic volvulus. There is no recurrence or long-term complications for the median 60 (20-119) month follow-up period. PTDH is a rare but serious complication. Majority of symptomatic cases present within the first postoperative year, whereas some late-presenting cases may not be symptomatic. Inadvertent injury to the inferior phrenic vasculatures due to excessive use of cauterization for control of hemostasis may be a plausible explanation in those cases.

Patterns of venous drainage of the left lateral section of the liver: a road map for anatomic resections

Patterns of venous drainage of the left lateral section of the liver: a road map for anatomic resections

Insights from Seoul National University Hospital's experience: a systematic review of pure laparoscopic donor hepatectomy progression.

Following its initial execution in November 2015, pure laparoscopic donor hepatectomy (PLDH) has gained acceptance as a conventional practice at Seoul National University Hospital (SNUH). It is noteworthy that a significant proportion of cases entail full right hepatectomies, which are acknowledged to be technically demanding. As expertise and knowledge have been accrued, the pure laparoscopic technique has been extended to encompass liver recipients as a viable option in SNUH. The aim of this review is to present the developmental progression of PLDH, with a focus on pure laparoscopic donor right hepatectomy (PLDRH), at SNUH. This includes the standardization process, which can be achieved by sharing the hospital's accumulated experience and previous reports. Various types of graft, including full right, left, left lateral section, and monosegment, were procured by pure laparoscopic technique. The criteria for selection were expanded to include donors with variations in the anatomy of the portal vein and bile duct. Additionally, the procedure of PLDRH was determined to be safe and viable for donors with high body mass index and larger graft weight. In conclusion, this review demonstrates the alterations implemented throughout our evolution from restricted to inclusive criteria for donor selection, leading to a complete shift from open surgery to pure laparoscopic procedures in donor hepatectomy and eventually pure laparoscopic living donor liver transplantation (LDLT) in recipient.

Technology Focus: Heavy Oil (April 2024)

Heavy oil can be one of the more technically challenging resources to recover. It is often easy to find but hard to move. This creates an incentive for knowledge seekers and problem solvers: The puzzle pieces are on the table; we just need to put them together. The physical characteristics of heavy oil and the formations in which it is found—the puzzle pieces—are often unique to a region or even to a specific asset, so recovery techniques must be tuned, adapted, and sometimes invented for each region. Creative professionals around the world are taking up this challenge and sharing their work with us in a wealth of excellent recent publications. In particular in our featured papers, we see three different parts of the world working with three different recovery techniques. First, we have a fundamental study in paper SPE 212779 of a perennial question from Canada’s oil sands: Where does the emulsion form in the steam-assisted gravity drainage (SAGD) recovery process, where the effect of a surfactant is studied? Moving south to paper SPE 213199, we review a study that progresses from laboratory work to field implementation using foam injection in Colombia in conjunction with cyclic steam stimulation. From Colombia, we look across to the other side of the world to paper SPE 215943, where we see a transition from steamflood recovery to an adapted configuration of SAGD, with a comprehensive discussion on optimizing production in Mukhaizna field in Oman. The theme of adaptation and invention continues in our recommended reading, with discussions of fundamental research, applied and practical insights on field implementation, and all the steps in between as these are applied to heavy oil production challenges around the world. I hope you enjoy the tour. Recommended additional reading at OnePetro: www.onepetro.org. SPE 212767 Part 1: Kinetics of Methane Exsolution From Bitumen in Thermal Recovery Processes—Experimental Study by Mohammad Khalifi, Imperial Oil Resources, et al. SPE 214113 Physical and Numerical Simulations of Offset Well Pair Combined Steam-Drive and Gravity-Drainage Process To Develop Superheavy Oil or Oil Sands Project by Guangyue Liang, China National Petroleum Corporation, et al. SPE 215342 Optimization of Chemical Acid Stimulation by Improving Selection Intervals in Lateral Section of Horizontal Well in X Field Heavy Oil Steamflood by Fatichin Fatichin, Pertamina, et al.

LOCOMOTOR ACTIVITY OF RATS WITH BLAST-INDUCED TRAUMATIC BRAIN INJURY IN A COMPLEX MAZE

Aim – to investigate the peculiarities of rats with blast-induced brain injury movement in the complex maze.Material and methods. The study was carried out on 15 sexually mature Wistar rats. All animals were randomly divided into 3 groups: experimental group (n=5), which was anesthetized and exposed to an air shock wave with an overpressure of 26-36 kPa; sham group (n=5), which was only anesthetized, and intact group (n=5). The study of locomotor activity was performed using a complex maze for 5 consecutive days, starting on the 1st day after the simulation of blast-induced brain injury. The route of rat`s movement through the maze of three groups was graphically depicted and visually analyzed.Results of the study. The complex maze is considered to be complicated due to the presence of a central zone and T-shaped branches to the right and left, ending with feeders. The complication of the situation and task lead to fear with rapid adaptation of healthy rats. However, if the brain functions are impaired, the experimental animal loses its physiological ability to adapt and shows signs of anxiety. The analysis of the images of the movement paths showed that on the 1st day of training, the rats of the experimental group moved more actively, despite the fact that the animals did not yet know that food was waiting for them. They performed monotonous movements and went to the side sectors more often. On 2nd day, the experimental rats were more active and explored the maze more stereotypically than intact animals. On 3rd and 4th days, clear signs of spatial memory impairment in the experimental group were found in terms of lengthening the path to the feeder. On the 5th day, it was found that the experimental rats were still poorly oriented in the maze, with a monotonous examination of the side sectors.Conclusions. Thus, mild blast-induced traumatic brain injury leads to persistent impairment of spatial memory, as well as behavioral disorders in the form of anxiety. The rats of the experimental group demonstrated stereotypical locomotor activity, as evidenced by the examination of the lateral sectors of the complex maze. At the same time, the memory for food reinforcement was well developed and retained.

Human and ecotoxicological risk assessment of heavy metals in polymer post treatment sludge from Barekese Drinking Water Treatment Plant, Kumasi

The disposal of polymer post-treatment sludge (PTS) from Barekese Water Treatment Plants (WTPs) as organic fertilizer and aquatic feed is a common practice in Ghana, necessitating a thorough evaluation of its ecological and human health risks. This study aims to assess the suitability of PTS samples for soil amendment and fish feed, scrutinizing potential hazards to consumer health and soil. PTS samples were collected from five distinct lateral sections of three clariflocculator tanks. Potentially toxic metals such as Cd, Zn, Pb, Cu, Ni, and Cr were determined using a flame atomic absorption spectrophotometer. The mean concentration of 7.82 ± 2.43, 0.31 ± 0.021, and 0.78 ± 0.042 mg/kg for Mn, Zn, and Pb respectively. The concentrations of Ni, Cr, and Cd were below their detection limits (BDL) in all PTS samples. Upon detailed exposure assessment, ingestion emerged as the primary exposure route for both adults and children, with non-cancer risks (NCR) determined to be below 1 for both age groups. Additionally, an exploration of potential cancer risks (CR) associated with heavy metal exposure in the PTS samples revealed values below the tolerable intake levels ranging from 10−4 to 10−6 for both adults and children (10−8 and 10−9, respectively). This study also employs various ecological indices, such as Nemerow's synthetic pollution index (PN), single factor pollution index (PI), geo-accumulation index (Igeo), contamination factor (CF), potential ecological risk index (PERI), pollution load index (PLI), polymetallic contaminant index (IPD), and ecological risk index (ERI). These indices consistently highlight a low contamination status and ecological sensitivity. Consequently, the study indicates that the presence of metals in the PTS samples does not pose a significant threat to the surrounding environment and human health. Furthermore, this research underscores the inadequacy of relying solely on regulatory limit values in assessing the health risks of waste materials. Such comprehensive assessments are crucial for safeguarding aquatic and human populations.

Dorsal approach in laparoscopic extended left hemi-hepatectomy: A case series.

The utility of the dorsal approach has been reported for laparoscopic left hemi-hepatectomy. The aim of the present study is to show the usefulness of the dorsal approach for laparoscopic extended left-hemi-hepatectomy while ensuring safe identification of hepatic veins and dissection of the dorsal tumor margin. Tumors requiring extended left hemi-hepatectomy. After mobilization of the lateral sector and division of the Arantius plate, parenchyma above the Arantius plate is removed to expose the root of the middle hepatic vein and left hepatic vein. Each of these veins can be isolated separately either intra- or extra-hepatically. After removing the parenchyma on the cranial side of the left Glissonean pedicle continuous with the exposed hepatic veins, the left Glissonean pedicle is isolated using the Glissonean pedicle transection method. After division of the left hepatic vein and Glissonean pedicle, segment 4 (in which the main part of the tumor is commonly located) is dissected from the anterior plane of the paracaval portion of the caudate lobe by the dorsal approach, along with the hepatic hilum. Following dissection of the dorsal side of the tumor, and division of parenchyma from the anterior edge of the liver, the anterior Glissonean branches and middle hepatic vein are divided safely and the specimen is resected. Three patients underwent laparoscopic extended left hemi-hepatectomy, with no open conversions. Operative time and blood loss were 331 (concomitant with another partial hepatectomy), 277, and 315 minutes; and 200, 100, and 100 g, respectively. The postoperative courses were uneventful. The dorsal approach maximizes the advantages of laparoscopic extended left hemi-hepatectomy and can be performed safely.

Research analysis on the airflow-particle migration and dust disaster impact scope by the moving mining truck in the open-pit mine

For the purpose of evaluating the dust disaster impact scenario in the open-pit mine, a full-scale physical model of the 730E Komatsu heavy mining truck has been constructed and simulated in the ANSYS Fluent software with the refined wheel tire cannelure structure. The results show that the wind velocity poses a stationary-fluctuation-recovery sector along the longitudinal. A clockwise ellipse separation vortex shapes at the chamber hopper and two symmetrical trailing vortexes arise behind the mining truck. The dust exhibits a saddle shape distribution in the lateral section and shows a gradual sedimentation in the longitudinal, while the percentage of ultrafine dust increases from 26.5% to 46.3%. The minimum safety distance 45 m is feasible to avoid the dust disaster impact from mining truck. The dust disaster impact area presents a linear decrease along the longitudinal direction. It displays an initial increase and later decrease as the vertical height rises. The dust disaster impact scope delineation derived from the moving mining truck has a vital scientific practical significance for ensuring the personnel health security and defining the dust precise prevention priority, which contributes to improving the occupational health level in the open-pit mine.

P-48 Post-traumatic Panhypopitutarism after an in-vehicle traffic accident: A case report

Abstract Introduction Hypopituitarism, occurs most commonly from pituitary tumors and a head injury, though a fracture of the base of the skull is considered a rare cause. Traumatic brain injury causes severe disability and endocrine dysfunction in a significant proportion of patients. Hypopituitarism diagnosed with endocrine symptoms related to hypoadrenocorticotropinemia, hypothyroidism and hypogonadism. We describe a case of posttraumatic panhypopitutarism presenting with symptoms of secondary amenorrhea, loss of appetite, nausea, vomiting, hearing loss and hypoglycemia after an in-vehicle traffic accident. Clinical Case A 28-year-old female patient with no medical history was admitted with symptoms of nausea, vomiting, anorexia, amenorrhea, and hypoglycemia after an in-vehicle traffic accident. It was learned that the patient's menstrual periods were regular before the accident and she did not have any complaints. Panhypopitutarism was observed in the examinations performed (Table 1). In the follow-ups, 10% intravenous dextrose solution and 20 mg prednisolone every 6 hours were started due to the hypoglycemic course. Prednisolone was reduced and discontinued, and hydrocortisone treatment was started from 30 mg/day. L-thyroxine replacement was started one week after the steroid treatment. Computed tomography (CT) showed deformity and collapse secondary to the fracture at the base of the sella and on contrast-enhanced pituitary magnetic resonance (MRI) imaging, it was observed that the morphology of the sella was distorted in T1-weighted sections, pituitary tissue could not be clearly distinguished, and there was collapse at the base of the sella in the right lateral section; the present findings were thought to support pituitary insufficiency (Figure 1). Hormone replacement therapy was given for secondary amenorrhea. One year after the accident, she wanted to be a pregnant and ovulation was induced by the injection of human menopausal gonadotrophin (HMG) following human chorionic gonadotrophin (HCG) at a large dose. She got pregnant in the first cycle. Conclusion In a patient with Panhypopituitarism, who could not be pregnant spontaneously, clinical practice of ovulation–induction treatment including administration of hCG and follicle-stimulating hormone, pulsatile GnRH (gonadotropin-releasing hormone), and in vitro fertilization, enabled the hypopituitary women to become ovulation and pregnancy. In our case, pregnancy was achieved after adequate hormone replacement therapy.Figure 1.CT and MRI images of the patientFigure. (a) Coronal CT section showing deformity-subsidence at the base of the sella secondary to fracture, (b and c) sagittal and coronal contrast-enhanced MRI showing subsidence at the base of the sella (thick arrow) with herniation of pituitary tissue (short arrow) and distorted-deformed infundibular stalk (thin arrow), respectively. Table 1.Laboratory workup*ACTH: Adrenocorticotropic hormone; FSH: follicle-stimulating hormone; LH: Luteinizing hormone; TSH: thyroid stimulating hormone; fT4: thyroxine; GH: Growth hormone; IGF-1: Insulin-like growth factor 1