External Tube Research Articles

Mediterranean fanworm, Sabella spallanzanii (Gmelin, 1791), as a potential biomonitor of trace metal pollution in the marine environment

Levels of trace metals (Cd, Cr, Cu, Fe, Ni, Pb, Mn, and Zn) were measured in soft tissues and external tubes of the Mediterranean fanworm, Sabella spallanzanii (Gmelin, 1791), to evaluate its suitability as a biomonitor of metal pollution. Study was conducted in the coastal area of the eastern Adriatic Sea. Polychaetes were collected from two locations, a site located in a local marina and an unpolluted control site. Results indicate that S. spallanzanii has the capacity to accumulate metals in soft tissues as well as in tubes. The levels of most metals were considerably higher in tubes compared to soft tissues, indicating long-term accumulation of metals in tubes. High levels of several metals (Cu, Zn, Cr, Pb and Fe), found in soft tissues and tubes sampled at the marina site, reflect the elevated contaminant levels in the marina, associated with the use of antifouling agents, paints, petrol additives, and ship maintenance activities. Metal concentrations in tissues and tubes generally decreased with size, indicating the influence of growth and metabolic rates on trace metal uptake. Trace metal levels found in S. spallanzanii tissues were comparable to the levels found in Mytilus galloprovincialis, a species commonly used in biomonitoring studies, in areas exposed to similar levels of anthropogenic stressors. According to the results of the present study, S. spallanzanii has been identified as a suitable biomonitor of metal pollution due to its sedentary nature, widespread distribution, abundance and the ability to accumulate high levels of metals within its tissues and tubes.

Compressive behavior of large-size square PEN FRP-concrete-steel hybrid multi-tube concrete columns

Fiber-reinforced polymer (FRP)-concrete-steel hybrid multi-tube concrete column (MTCC) is a new type of composite column and comprises a number of steel inner tubes, an FRP external tube and concrete fillings for the space inside all the tubes. This paper presents a series of experimental tests on four large-size square PEN (polyethylene naphthalate) FRP-MTCCs, of which the PEN fibers were extracted from recycled plastic bottles. The parameters of interest include the FRP thickness and the steel tube configuration. The experimental results showed that the large-size square MTCCs with PEN FRP exhibited excellent ductility due to the effective confinement provided by PEN FRP jacket and steel tubes. A prediction method for the square PEN FRP-MTCCs has been developed in the present study to consider the unique characteristics of the column and is able to produce reasonable predictions for the experimental results. This study serves to present an innovative alternative in an environmentally friendly way that can replace the conventional bridge piers in coastal and salina regions.

Stage-dependent function of Wnt5a during male external genitalia development.

External genitalia development in mice involves multiple developmental processes under the regulation of various signaling pathways. Wnt5a, one of the major Wnt ligands, is a crucial developmental regulator of outgrowing organs such as the limb, the mandible, and the external genitalia. Defects in Wnt5a signaling have been linked to Robinow syndrome, a genetic disorder in which male patients manifest a micropenis and defective urethral tube formation. Whereas Wnt5a is required for cell proliferation during embryonic external genitalia outgrowth, its role for urethral tube formation has yet to be understood. Here, we show that Wnt5a contributes to urethral tube formation as well as external genitalia outgrowth. Wnt5a is expressed in the embryonic external genitalia mesenchyme, and mesenchymal-specific conditional Wnt5a knockout mice resulted in hypospadias-like urethral defects. Early deletion of Wnt5a at E10.5 showed severe defects in both external genitalia outgrowth and urethral tube formation, along with reduced cell proliferation. The severe urethral tube defect persisted during later timing deletion of Wnt5a (E13.5). Further analyses revealed that loss of Wnt5a disrupted cell polarity and led to a reduction of the phosphorylated myosin light chain and the focal adhesion protein, vinculin. Altogether, these results suggest that Wnt5a coordinates cell proliferation and directed cell migration in a stage-dependent manner during male external genitalia development. Furthermore, Wnt5a may regulate cell polarity, focal adhesion formation, and cell contractility, leading to directed cell migration during male-type urethral formation in a manner that has not been reported in other organ fusion events.

Results of Using the Cystic Duct for Reconstruction of One of the Multiple Bile Ducts in Right Lobe Living Donor Liver Transplantation

In right-lobe liver grafts, variations in the biliary tree anatomy can result in multiple bile duct orifices. We present our experience of 10 patients in which biliary reconstruction was performed with the cystic duct for 1 of the anastomoses with 2 separated ducts. Also, we investigated whether the bile duct anastomosis technique, number of bile duct anastomoses, and use of biliary stents affect the rate of biliary complications. We evaluated patients who underwent right-lobe living donor liver transplantation (LDLT) at İstinye University Hospital and İstanbul Aydın University Hospital between December 2017 and June 2020. The patients were divided into 4 groups: duct-to-duct (D-D), duct-to-sheath, double duct-to-duct, and duct-to-duct plus cystic duct-to-duct. Biliary complication rates were compared among these 4 groups, between single- and double-duct groups, and between stent (+) and stent (-) groups. Ninety-three patients who underwent right-lobe LDLT (60 men, 33 women) with a mean age of 51 ± 13 years were included. Mean follow-up time was 18.5 ± 8.3 months. The overall biliary complication rate was 17.2% for all patients, 12.1% for the D-D (single-duct) group (33 patients), 16.1% for the duct-to-sheath group (31 patients), 26.3% for the double duct-to-duct group (19 patients), 20% for the duct-to-duct plus cystic duct-to-duct group (10 patients), 20% for the double-duct group (60 patients), 14.5% for the stent (+) group (69 patients), and 25% for the stent (-) group (24 patients). There were no significant differences among these groups in terms of biliary complication rates. Bile stricture occurred in only 1 cystic duct anastomosis (10%), and no bile leakage was observed. Multiple D-D biliary reconstruction using the cystic duct with external drainage tubes is feasible and safe for LDLT.

Outcomes of early reoperation in severe pancreatic fistula and/or haemorrhage after pancreaticoduodenectomy

Although advances in multidisciplinary management reduce the mortality after pancreaticoduodenectomy (PD) from medical complications, postoperative pancreatic fistula (POPF) and/or postpancreatectomy haemorrhage (PPH) still remain as common morbidities and main causes of mortality. The morbidity of POPF and/or PPH after PD in our centre, Yangon Specialty Hospital, is 18-30% per year. And there are still ongoing disputes regarding management of POPF and/or PPH after PD. It is a hospital based prospective descriptive study carried out between 2018 January and 2020 April in surgical units at Yangon General Hospital, New Yangon General Hospital and our centre. Total 28 reoperated patients with POPF and/or PPH patients after PD were included in the study. The indications for reoperation in this study were patients with SIRS together with drain amount more than 300 ml/day and/or blood in drain/ NGT with Hb drop ≥ 3 g% or sentinel bleed. Preoperative CECT scan was done if condition was favorable. In this study, demographic distribution, proportion of reoperation, timing of reoperation, types of procedure were also recorded while outcomes of reoperation was emphasized in this eposter. There were 56 patients who suffered from POPF and/or PPH after PD for periampullary carcinoma during this study period. Although reoperation was advised to 34 patients, who met the indications for reoperation, six of them declined operation for various reasons. Therefore, total 28 patients were reoperated (50%). Fig. 1 showed the intraoperative findings of POPF and PPH patient. Median timing of reoperation was 9 days (2-25 days) and 71% were reoperated within 10 days. While external tube wirsungosotmy (Fig. 2) was performed in majority of POPF cases as a damage control surgery, PPH patients ended up with mainly laparotomy and GDA ligation for arrest of haemorrhage because of lack of interventional radiology (IR) support at present. Among reoperated patients, 14 patients (50%) survived and 14 patients (50%) expired. Therefore, overall in-hospital mortality was 50% in reoperated cases. The main cause was multi-organ failure due to severe sepsis. According to the Fig. 3, in-hospital mortality rate of POPF was 16% and that of PPH was 66% while that of POPF and PPH was 80% in this study. Gangl et al. (2011) [1] reported that the combination of pancreatic fistula and severe hemorrhage was a strong predictor of postoperative mortality (relative risk (RR), 22.75). And Tamijmarane et al. (2006) [2] pointed out that patients themselves are in such a moribund condition that their associated mortality rate ranges between 38 and 50%. In addition, it was surprisingly found that all six patients, who needed reoperation, died with conservative management in this study. It is found that reoperation is necessary in patients when it is indicated i.e. mainly clinical based. Early reoperation and damage control surgery is found to have better outcomes in especially POPF patients before organ failure or haemorrhage supervenes. And it is hard to say the accurate timing of reoperation and optimal procedures because this study has some limitations like small sample size, and limited resources for multidisciplinary management. Therefore, further study with larger sample size and optimal resources and management will be necessary for better and more significant results. Showing intraoperative findings of POPF and PPH. Showing method of external tube Wirsungostomy insertion. Outcomes of reoperative management.

ENHANCEMENT OF HEAT TRANSFER IN DOUBLE PIPE HEAT EXCHANGER USING AL2O3-FE2O3/WATER HYBRID NANOFLUID

This study aims to enhancement of heat transfer in double pipe heat exchanger by improving the thermal properties of base fluid which is water by adding AL2O3-Fe2O3 nanoparticles to the water. Al2O3-Fe2O3/water hybrid Nanofluid were examined experimentally and numerically at different flow rates ranging between (3 -7) Lpm at temperature of 25°C in an external tube while there was a hot water at a temperature of 60°C and a flow rate ranged between (3 – 5) Lpm running in the central tube of a double pipe counter heat exchanger. Also, the effect of various concentrations ranged between (0.05, 0.1, 0.15, 0.2, 0.25 and 0.3%) of Al2O3-Fe2O3 nanoparticles dispersed in water on the rate of heat transfer, friction coefficient were verified experimentally and numerically . The ratio of Al2O3-Fe2O3 is 0.5:0.5. The experimental and numerical study indicated that with the rate of heat transfer increases when the concentration of suspended nanoparticles in the base fluid increases , but on the other hand, the skin friction coefficient and pressure drop increases as well with increasing the concentration of nanoparticles. The maximum enhancement in heat transfer for AL2O3-Fe2O3 is about 6 % . The results from the experimental study were largely consistent with the numerical results.

Experimental Investigation to Evaluate the Behavior of Concrete-Filled Steel Tubular Columns under the Effect of the Distribution of the ‎Total Steel Area between the Internal Concrete Core and the External Steel Tube

Composite columns are generally installed in high-rise buildings and bridges. As well as being smaller and lighter than conventional reinforced concrete columns, composite columns offer high efficiency and ductility. In this research, experimental and analytical studies were carried out to investigate the optimal distribution of the ‎total steel area of the Concrete-Filled Hollow Steel Tube (CFHST) columns; the experimental program included 20 CFHST columns. ‎The main variables of the experimental study were the distribution of the total steel cross-sectional area over the internal concrete core (steel reinforcement) and the external steel tube, the cross-sectional shape, the width-to-breadth ratio t/b, and the presence or absence of shear connectors. In addition, using equations of different codes, comparison was conducted between the experimental and analytical results. For a constant steel cross-sectional area, the use of internal steel bars and external steel tubes, together with the use of shear connectors, was found to exhibit a better ultimate load capacity, stiffness, and ductility for the CFHST columns.

CALCULATION METHOD FOR IMPACT RESISTANCE OF CIRCULAR CONCRETE-FILLED DOUBLE-SKIN TUBULAR COLUMNS WITH EXTERNAL STAINLESS STEEL TUBE

Reinforced concrete and concrete-filled steel tubular members have been widely used in engineering structures and the design methods for the impact resistance have been suggested. However, studies on the impact resistance of circular concrete-filled double-skin tubular (CFDST) columns with external stainless steel tubes are limited. In light of this, the finite element analysis (FEA) model considering the coupling effect of axial and impact loads was established by ABAQUS based on preliminary experimental research. The impact mechanism under the combined action of axial and impact loads was investigated. The effects of axial load ratio, nominal steel ratio and other parameters on the impact resistance were studied. The formula used to predict the dynamic increase factor (DIF) of the plateau impact force subjected to axial and impact loads was suggested. The results show that the plastic deformation of outer steel tube is the main energy dissipation mechanism of members. Axial load ratio has a negative effect on the impact resistance of members, and the effect is significant when the axial load ratio exceeds 0.5. Nominal steel ratio, strengths of outer tube and concrete, impact velocity and cross-sectional diameter have significant effects on the impact resistance of members. The formula suggested in this study can reasonably predict the plateau impact force of members under lateral impact.

Confining stress path-based compressive strength model of axially compressed circular concrete-filled double-skin steel tubular short columns

Previous investigations have shown that the confining stress paths (CSPs) of confined concrete significantly affected the compressive behaviour of confined concrete in fibre-reinforced polymer (FRP) confined concrete or concrete-filled steel tube (CFST) columns. Unlike the concrete in FRP-confined concrete or CFST columns, which is only confined by external materials, e.g., FRP sheet or steel tube, the concrete in concrete-filled double-skin steel tubular (CFDST) columns is confined by both the external and internal steel tubes. Due to different confinement mechanisms, the CSPs of confined concrete in CFDST columns may be different from those in FRP-confined concrete or CFST ones, but they have not been investigated so far. In this paper, the CSPs of confined concrete in circular CFDST stub columns were experimentally investigated, and their corresponding influences on the compressive strength were also discussed. It is shown that the CSPs of confined concrete induced by the external tube are considerably influenced by column variables, whereas those generated by the internal tube found no obvious trend. Moreover, the results suggest that the compressive strength of confined concrete in specimens with a confinement coefficient η less than 2.731 is CSP-dependent, based on which, a compressive strength model of confined concrete considering the CSP effect is developed for circular CFDST columns. Based on this model, a CSP-based compressive strength model for estimating the ultimate strength of CFDST columns is proposed, and comparison with existing models against the collected test data indicates a higher accuracy of the predictions for the proposed model.

Diversity and emendation of the genus Planktoniella (Bacillariophyceae), with descriptions of P.tubulata sp. nov. and P.trifurcata sp. nov.

For the first time, LSU and SSU sequences were obtained from four species of the marine planktonic diatom Planktoniella. Samples were collected and cultured from Chinese coastal waters, and morphological observations were made using light and scanning electron microscopy. Combined morphological and DNA sequence data revealed two new species herein described as Planktoniella tubulata and Planktoniella trifurcata. Planktoniella tubulata is characterized by the prominent external tubes of two rimoportulae and the long external tubes of the marginal fultoportulae. The latter are organized regularly in a ring, externally on the mantle, and protrude parallel to the valvar plane. Planktoniella trifurcata is unique in having mucilaginous extensions that usually expand into three lobes, and external extensions of the marginal fultoportulae being either tubes or spines. In the phylogenetic analyses inferred from SSU and LSU sequences, the four analyzed Planktoniella taxa formed a well-supported monophyletic group. A suite of three characters, mucilage membranes or wings, two marginal rimoportulae, and mantle ribs are diagnostic for Planktoniella. Based on these detailed ultrastructural observations, the description of Planktoniella is emended.

A Retrospective Analysis of the Effectiveness of Extrapleural Autologous Blood Patch Injection on Pneumothorax and Intervention Need in CT-guided Lung Biopsy.

To assess the effect of extrapleural autologous blood injection (EPABI) technique on pneumothorax development before and after coaxial needle withdrawal (CNW) and intervention rate for pneumothorax. To analyze the risk factors of pneumothorax and parenchymal hemorrhage. The records of 288 patients who had lung biopsies were analyzed. Of these patients, 188 received EPABI (group-A) before penetrating the parietal pleura, and the remaining did not (group-B). Intraparenchymal autologous blood patch injection was applied at the end of the procedure. The pneumothorax rates before/after CNW and intervention requirement for pneumothorax were compared between groups. The risk factors of pneumothorax before/after CNW and parenchymal hemorrhage were assessed with stepwise logistic regression. The pneumothorax rate before CNW was significantly lower in group-A (5.92%) than in group-B (19.10%) (p = 0.029). Pneumothorax risk before CNW was reduced if EPABI was applied and skin-to-pleura distance increased. The pneumothorax rate after CNW was similar between two groups (group-A: 6.94%, group-B: 8%), while emphysema grade along the needle path and procedure duration was the significant risk factor. The intervention requirement for pneumothorax was significantly lower in group-A (6.38%) than in group-B (16%) (p = 0.012). Needle aspiration requirement was significantly reduced in group-A. The rate of external drainage catheter and chest tube placement was similar in both groups. The risk factors of parenchymal hemorrhage were overall emphysema grade of the lung, target-to-pleura distance, and target size. Use of EPABI along with IAPBI significantly decreased the pneumothorax rate during biopsy procedure and the intervention rate compared to IAPBI-alone.

Intractable Biliary Strictures After Living Donor Liver Transplantation: A Case Series

Biliary stricture (BS) is a severe complication after liver transplantation. It is difficult to treat, especially after living donor liver transplantation (LDLT). We successfully treated 4 patients for intractable BS after LDLT. All patients had developed cholangitis with stenosis of bile ducts anastomosis. CASE 1: . A 65-year-old woman underwent LDLT with right lobe graft and duct-to-duct biliary reconstruction. Internal plastic stents inserted by endoscopic retrograde cholangiography (ERC) were changed quarterly for the next 2 years. CASE 2: A 55-year-old man underwent LDLT with right lobe graft and duct-to-duct biliary reconstruction. Insertion of internal plastic stents by ERC was attempted; however, the posterior bile duct branch showed complete obstruction. After percutaneous transhepatic biliary drainage (PTCD), the stents were inserted using the rendezvous technique of ERC and were changed by ERC quarterly for the next 3 years. CASE 3: A 22-year-old man underwent LDLT with left lobe graft and hepaticojejunostomy. An external drainage tube was inserted by PTCD, and stents were changed quarterly for the next 2 years. CASE 4: A 60-year-old man underwent LDLT with right lobe graft and hepaticojejunostomy. An external drainage tube was inserted by PTCD, and changed to a metallic stent after 1 year. Three months later the stent was extracted using the rendezvous technique of double balloon enteroscopy. BS of complete obstruction type after LDLT is difficult to treat. Appropriate procedures should be chosen based on the types of strictures and biliary reconstruction methods.

Application of dual-channel contrast-enhanced ultrasound in classification of hilar cholangiocarcinoma and diagnosis of etiology of low biliary obstruction

Objective: To investigate the clinical value of dual-channel contrast-enhanced ultrasound (DCUS) in the classification of hilar cholangiocarcinoma and the diagnosis of the etiology of low obstructive jaundice. Methods: The data of 114 patients with obstructive jaundice examined by the Department of Ultrasound of Lanzhou University Second Hospital from October 2018 to February 2020 were retrospectively collected. There were 60 males and 54 females, aged 37~84 (63±10) years. All patients underwent preoperative transvenous contrast-enhanced ultrasound (CEUS), intraoperative puncture needles, postoperative ultrasound-guided percutaneous transhepatic cholangiocarcinography (UG-PTC) and three-dimensional ultrasound cholangiography (3D-USC) through an external drainage tube, known as DCUS. The classification of hilar cholangiocarcinoma and the nature of low biliary tract obstruction were determined according to the characteristics of DCUS images. All patients who have received DCUS underwent magnetic resonance cholangiopancreatography (MRCP) and X-ray cholangiography. X-ray cholangiography was used as the gold standard for classification of hilar cholangiocarcinoma, and the accuracy of US, CEUS and DCUs was analyzed. Low obstructive jaundice was characterized by surgical pathology as the gold standard, and the diagnostic efficacy of conventional ultrasound (US), CEUS and DCUs was analyzed. At the same time, the receiver operating characteristic (ROC) curve was used to compare the efficacy of MRI+MRCP and DCUS in determination of the nature of low biliary obstruction. Results: The coincidence rates of US, CEUS, and DCUS in the classification of hilar cholangiocarcinoma and X-ray cholangiography were: 75.6% (34/45), 82.2% (37/45), and 93.3% (42/45), respectively. The coincidence rates of US, CEUS, and DCUS in the determination of the nature of low biliary obstruction and surgical pathology were 56.5% (39/69), 82.6% (57/69), and 85.5% (59/69), respectively. Compared with conventional ultrasound, CEUS had no statistically significant difference in the diagnosis of hilar cholangiocarcinoma (P=0.438), and DCUS had statistically significant difference in the diagnosis of hilar cholangiocarcinoma (P=0.039).ROC curve analysis suggested that the cut-off value of MRI+MRCP grade and DCUS grade for diagnosing benign and malignant low biliary obstruction were both 2.5; the area under the curve (AUC) were 0.897 and 0.906, respectively (both P<0.01); sensitivity were 77.5% and 93.1%, respectively; and the specificity were 87.5% and 82.8%, respectively. Conclusion: The value of DCUS in the classification of hilar cholangiocarcinoma and the qualitative diagnosis of low biliary tract obstruction was comparable to that of X-ray cholangiography and MRCP. DCUS had important clinical application value in the classification of hilar cholangiocarcinoma and the etiological diagnosis of low obstructive jaundice.

Analytical model for local bulging failure of mini-BRBs with circular restraint tubes

This paper proposes an analytical model for predicting local bulging failure of mini-BRBs with circular restraining tubes. The mini-BRB consists of a quasi-triangular core bar and an external circular restraining tube, and bulging of the tube can occur due to thrust of the inner core bar buckling in high-order mode. To analyze the mechanism of bulging, 4 specimens were designed with restraining tubes of different thicknesses, and strain gauges were attached to external surfaces of tubes to record strain distribution and development during the bulging process. An analytical model was established to obtain the lateral thrust versus bulging depth relationship, and a criterion was proposed to define the bulging resistance of circular tube. Numerical analysis was conducted and the results of which were employed to modify theoretical bulging resistance. Finally, based on experiment results, a performance-based design criterion with a safety factor considering the estimated maximum lateral thrust and the bulging resistance of tube was proposed to prevent premature local bulging failure.

Experimental Study on Short Steel Tube Columns Filled with Recycled Large Aggregate-Self Compacting Concrete Subjected to Compression

The mechanical characteristics of recycled large aggregate concrete show poorer performance than that of Portland-cement concrete due to the internal defects of recycled large aggregate (RLA). To improve the mechanical characteristics of recycled large particle size aggregate concrete, the recycled large aggregate Self-Compacting Concrete filled steel tube (RLA-SCCFST) is proposed. The external steel tube can not only keep the core recycled large aggregate concrete in the three-dimensional state of stress, but also prevent the crack expansion of the core recycled large aggregate concrete. RLA-SCCFST subjected to compression is studied experimentally. The compression failure tests use 20 specimens of circular section short column with different steel content rate, particle size of RLA, strength of RLA, strength of SCC, and eccentricity of the load. The influence of different factors on mechanical characteristics of RLA-SCCFST short cylindrical components subjected to compression is analyzed. The results indicate that the load-bearing performance of RLA-SCCFST short columns increases following with the augmentation of RLA particle size, strength of RLA particle size, strength of SCC and steel content rate. The load-bearing performance of RLA-SCCFST short columns reduced with the augmentation of the load eccentricity. And the experimental results are in high coincidence with those calculated by different formulas.

Role of endoscopic ultrasonography in the management of peripancreatic collections.

Pancreatic fluid collections are surrounded by a wall of granulation tissue and may contain necrotic debris. They occur following a severe acute pancreatitis and most of the cases resolve spontaneously after several weeks. However, their management may lead to a very hard-to-treat condition, requiring a multidisciplinary approach. During the last decades we assisted to a change of paradigm involving Endoscopic Ultrasonography, from a pure diagnostic technique to an interventional-therapeutic one, allowing an effective, safe and less invasive approach than other existing treatment standards, historically consisting of surgical and percutaneous drainage. Treatment of pancreatic fluid collections is indicated if they become infected or symptomatic. Over the past years, exponential developments were done in interventional endoscopic approach, making it the first line suggested modality. The use of endoscopic ultrasound allows assessment of the collection, even when it is not directly bulging on gastrointestinal wall, creation of an internal fistulous tract, checking for surrounding vessels with the use of Doppler, and deployment of a stent avoiding the discomfort of external tubes. Several types of stent have been used for endoscopic drainage: plastic double pigtail stents, fully covered self-expanding metal stents and, more recently, lumen apposing metal stents, which are considered revolutionary because of their two-side flanges and wide and short internal channel, a new design that made easier direct endoscopic necrosectomy. This review aims to go through currently available literature on the diagnostic and therapeutic role of endoscopic ultrasonography to handle pancreatic fluid collections.

First Data on the Parasites of the Pacific Kingcroaker Menticirrhus elongatus (Perciformes: Sciaenidae): Description of a New Species of Rhamnocercoides (Dactylogyridea: Diplectanidae).

A new monogenean, Rhamnocercoides lambayequensis n. sp. (Dactylogyridea: Diplectanidae), is described based on the specimens collected from the gills of the Pacific kingcroaker Menticirrhus elongatus (Günther 1864) (Perciformes: Sciaenidae), a demersal fish endemic to Eastern Pacific, captured off the South American Pacific coast, Lambayeque Region, Peru. Monogeneans were fixed in hot 4% formalin. Some monogeneans were transferred directly onto a slide in a drop of glycerin-ammonium picrate mixture (GAP). Others were mounted stained with Gomori's trichrome in Canada balsam. Drawings were made using of a drawing tube. The new species is mainly characterized by its MCO, which is tubular and straight, with external (distally expanded and bifurcated) and internal tubes (distally uncovered by external tube). Rhamnocercoides lambayequensis n. sp. is also characterized by having the following features: a weakly sclerotized almost pyriform vagina; haptoral acicular spines with expanded distal portion and by having a small group of haptoral accessory spines associated with haptoral lobes arranged as spikes. This is the first data on the parasites of M. elongatus, a little known, but popular fish in local markets. The present finding brings to two, the number of known species of Rhamnocercoides Luque and Iannacone 1991, and represents the sixth described marine diplectanid species infecting sciaenid fishes from Peru.

Thermal Analysis of a Solar External Receiver Tube with a Novel Component of Guide Vanes

The heat transfer performance of a solar external receiver tube with guide vanes was numerically studied under non-uniform heat flux conditions. Models of the smooth tube and the tube with guide vanes were built. The distributions of the temperature, velocity, turbulence intensity, and Nu predicted by these two models were compared to investigate the heat transfer enhancement and the mixing effect of the guide vanes. The effect of the Re and the α on the heat transfer enhancement was also studied. The results show that the guide vanes form spiraling flows, reduce the maximum tube and molten salt temperatures, and improve the heat transfer. In addition, a more uniform temperature distribution is achieved compared to the smooth tube, allowing the molten salt to work safely under higher heat flux conditions in the receiver tube with guide vanes. It was observed that a larger Re enhances the heat transfer on the tube wall and achieves a longer effective distance of enhanced heat transfer in the downstream region, while the spiraling flow, the heat transfer enhancement, and the mixing are stronger for a larger α.

Laparoscopic cholecystectomy after endoscopic trans-papillary gallbladder stenting for acute cholecystitis: a pilot study of surgical feasibility

BackgroundPercutaneous transhepatic gallbladder drainage (PTGBD) is indicated for patients with acute cholecystitis (AC) who are not indicated for urgent surgery, but external tubes reduce quality of life (QOL) while waiting for elective surgery. The objective of the present study was to investigate the feasibility of laparoscopic cholecystectomy after endoscopic trans-papillary gallbladder stenting (ETGBS) comparing with after PTGBD.MethodsIntraoperative and postoperative outcomes of patients with ETGBS and PTGBD were retrospectively compared.ResultsEighteen ETGBS and ten PTGBD patients were compared. Differences in the duration of ETGBS and PTGBD [median 209 min (range 107–357) and median 161 min (range 130–273), respectively, P = 0.10], median blood loss [ETGBS 2 (range 2–180 ml) and PTGBD 24 (range 2–100 ml), P = 0.89], switch to laparotomy (ETGBS 11% and PTGBD 20%, P = 0.52), and median postoperative hospital stay [ETGBS 8 (range 4–24 days) and ETGBS 8 (range 4–16 days), P = 0.99]. Thickening of the cystic duct that occurred in 60% of the ETGBS patients and none of the PTGBD patients (P = 0.005) interfered with closure of the duct by clipping. No obstruction occurred in ETGBS patients.ConclusionETGBS did not make laparoscopic cholecystectomy less feasible than after PTGBD. This is a pilot study, and further investigations are needed to validate the results of the present study.

Omentoplasty decreases deep organ space surgical site infection compared with external tube drainage after conservative surgery for hepatic cystic echinococcosis: Meta-analysis with a meta-regression.

The rate of deep organ space/surgical site infection after conservative surgery for hepatic cystic echinococcosis (HCE) ranges from 12% to 26% with a post-operative mortality rate between 0% and 7.5%. This systematic review with meta-analysis aimed to investigate whether omentoplasty (OP) following conservative surgery for HCE leads to decreased rates of morbidity and mortality compared to external tube drainage ETD. We identified 4540 articles through database searching. After verifying the inclusion and exclusion criteria, we retained eight studies for final analysis: two randomized controlled trials (RCT), one prospective comparative study and five retrospective comparative studies. The main outcome measure was organ space/surgical site (OS/SS) morbidity that was limited to "deep organ space/surgical site infection (Deep OS/SSI) with or without re-operation". The eight studies reported results for deep OS/SSI (6/374 (OP) and 60/403 (ETD), respectively). There were statistically significantly less deep OS/SSI with OP (vs. ETD) OR=0.17 95%CI [0.05, 0.62] (P=0.007). A random-effect meta-regression, including the eight studies, showed an interaction in favor of OP. There were also statistically significant less biliary leakage±fistula and overall morbidity in OP compared to ETD. On the other hand, no statistically significant difference was found concerning deep bleeding, mortality and recurrence between these two groups. This meta-analysis with a meta-regression showed that there were statistically significant less deep OS/SSI, biliary leakage±fistula and overall morbidity in OP compared to ETD.