Resistance Index Values Research Articles

Assessment of the Suitability of Coke Material for Proppants in the Hydraulic Fracturing of Coals.

To enhance the extraction of methane gas from coal beds, hydraulic fracturing technology is used. However, stimulation operations in soft rocks, such as coal beds, are associated with technical problems related mainly to the embedment phenomenon. Therefore, the concept of a novel coke-based proppant was introduced. The purpose of the study was to identify the source coke material for further processing to obtain a proppant. Twenty coke materials differing in type, grain size, and production method from five coking plants were tested. The values of the following parameters were determined for the initial coke: micum index 40; micum index 10; coke reactivity index; coke strength after reaction; and ash content. The coke was modified by crushing and mechanical classification, and the 3-1 mm class was obtained. This was enriched in heavy liquid with a density of 1.35 g/cm3. The crush resistance index and Roga index, which were selected as key strength parameters, and the ash content were determined for the lighter fraction. The most promising modified coke materials with the best strength properties were obtained from the coarse-grained (fraction 25-80 mm and greater) blast furnace and foundry coke. They had crush resistance index and Roga index values of at least 44% and at least 96%, respectively, and contained less than 9% ash. After assessing the suitability of coke material for proppants in the hydraulic fracturing of coal, further research will be needed to develop a technology to produce proppants with parameters compliant with the PN-EN ISO 13503-2:2010 standard.

Influence of hyperthermic intraperitoneal chemotherapy on renal blood perfusion

PurposeHyperthermic intraperitoneal chemotherapy (HIPEC) is accompanied with an increased risk of acute kidney injury (AKI). Whether AKI is induced by chemotoxicity or hyperthermia-related changes in renal perfusion remains controversial. The influence of HIPEC on renal perfusion has not been evaluated in patients yet.MethodsRenal blood perfusion was assessed in ten patients treated with HIPEC by intraoperative renal Doppler pulse-wave ultrasound. Ultrasound (US) examinations were performed pre-, intra-, and postoperative with analyses of time-velocity curves. Patient demographics, surgical details, and data regarding renal function were recorded perioperatively. For evaluation of renal Doppler US to predict AKI, patients were divided in two groups with (AKI +) and without (AKI −) kidney injury.ResultsThroughout HIPEC perfusion, neither significant nor consistent changes in renal perfusion could be observed. Postoperative AKI occurred in 6 of 10 participating patients. Intraoperative renal resistive index (RRI) values > 0.8 were observed in one patient developing stage 3 AKI according KDIGO criteria. At 30 min in perfusion, RRI values were significantly higher in AKI + patients.ConclusionAKI is a common and frequent complication after HIPEC, but underlying pathophysiology remains elusive. High intraoperative RRI values may indicate an increased risk of postoperative AKI. Present data challenges the relevance of hyperthermia-derived hypothesis of renal hypoperfusion with prerenal injury during HIPEC. More attention should be drawn towards chemotoxic-induced hypothesis of HIPEC-induced AKI and caution applying regimens containing nephrotoxic agents in patients. Further confirmatory and complementary studies on renal perfusion as well as pharmacokinetic HIPEC studies are required.

(165) Role of Penile Veno-occlusive Dysfunction in Peyronie’s Disease Patients with Erectile Dysfunction

Abstract Introduction The incidence of Peyronie's disease (PD) is 4% in the U.S. male population. Many PD patients also suffer from erectile dysfunction (ED). The etiology of ED incidence in PD men is not known, although veno-occlusive dysfunction (VOD) is often suggested. It is important to appreciate the influence of VOD in PD patients with ED, especially in regard to successful PD treatment. Objective The main objective of this study is to assess the penile hemodynamic response to intracavernous injection (ICI) of a vasoactive agent in order to evaluate the incidence of VOD in PD patients with or without ED. Methods A total of 333 men, diagnosed either with PD (n=202) or ED (n=68) or both PD and ED (n=63), visiting our Andrology clinic were included in this study. Initial ED was determined by using the International Index of Erectile Function (IIEF) score, whereas patients with penile curvature ≥30° were categorized as having PD. Penile color duplex Doppler ultrasound (CDDU) data was retrospectively collected from these patients, and parameters such as peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) were used for analysis. RI (=PSV-EDV/PSV) was calculated, and VOD was confirmed when PSV ≥30 cm/sec, EDV ≥6 cm/sec, and RI <0.8 based on previously published guidelines for standardization of penile CDDU parameters. Statistical analysis was performed using MedCalc statistical software version 20.019 (MedCalc Software bv, Ostend, Belgium). Results Table 1 summarizes the CDDU results of all 333 patients. Age of the study subjects was 55.6 ± 11.3 years, with no difference between groups. Incidence of penile VOD was higher in patients with ED without PD (58.8%) or with PD (52.4%) compared to PD alone (44.6%). RI values of PD patients without ED were higher (>0.8) compared to PD patients with ED having VOD (<0.7) (P<0.001). Conclusions The current study results indicate that lower RI values suggest a higher incidence of VOD in PD patients. VOD plays an important role in the onset of ED in men with PD. Furthermore, this demonstrates the importance of performing CDDU and diagnosing the presence of VOD in further understanding the pathophysiology of PD. Disclosure No

Molecular detection and antimicrobial resistance profiles of Extended-Spectrum Beta-Lactamase (ESBL) producing Escherichia coli in broiler chicken farms in Malaysia.

Antimicrobial resistance is one of the major public health threats globally. This challenge has been aggravated with the overuse and misuse of antibiotics in food animals and humans. The present study aimed to investigate the prevalence of Extended-Spectrum β-lactamase (ESBL) genes in Escherichia coli (E. coli) isolated from broiler chickens in Kelantan, Malaysia. A total of 320 cloacal swabs were collected from farms in different districts of Kelantan and were analyzed using routine bacteriology, antimicrobial susceptibility test, and molecular techniques for further identification and characterization of ESBL encoding genes. Based on PCR detection for the E. coli species-specific Pho gene, 30.3% (97/320) of isolates were confirmed as E. coli, and 84.5% (82/97) of the isolates were positive for at least one ESBL gene. Majority of the isolates, 62.9% (61/97) were harboring blaCTX-M followed by 45.4% (44/97) of blaTEM genes, while 16.5% (16/97) of the isolates were positive for both mcr-1 and ESBL genes. Overall, 93.8% (90/97) of the E. coli were resistant to three or more antimicrobials; indicating that the isolates were multi-drug resistance. 90.7% of multiple antibiotic resistance (MAR) index value greater than 0.2, would also suggest the isolates were from high-risk sources of contamination. The MLST result shows that the isolates are widely diverse. Our findings provide insight into the alarmingly high distribution of antimicrobial resistant bacteria, mainly ESBL producing E. coli in apparently healthy chickens indicating the role of food animals in the emergence and spread of antimicrobial resistance, and the potential public health threats it may pose.

Prevalence of multidrug-resistant and extended-spectrum β-lactamase-producing Escherichia coli from chicken farms in Egypt.

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli strains exhibit antibiotic resistance and are known to infect humans worldwide. This study assessed the phenotypic and genotypic prevalence of ESBL-resistant E. coli isolates recovered from the respiratory tracts of chickens in El-Sharkia Governorate, Egypt. We obtained 250 lung samples (one lung/bird) from 50 chicken farms (5 chickens/farm) to isolate, identify, and serotype E. coli. Antimicrobial resistance susceptibility was determined using the disk diffusion method, while the ESBL phenotype was identified using double disk synergy. We detected the β-lactamase genes, blaTEM, and blaSHV, using a polymerase chain reaction. The results showed that 140/250 (56%) were infected with E. coli. All the serogroups of isolated E. coli exhibited high multi-antimicrobial resistance index values (>0.2), and 65.7% were confirmed to have ESBL. Among the isolates with the ESBL phenotypes, 55 (60%) and 32 (35%) contained the blaTEM and blaSHV genes, respectively. The widespread distribution of multidrug-resistant and ESBL-producing E. coli among poultry farms is a significant human health hazard. These results will help the Egyptian authorities to implement a national one-health approach to combat the antimicrobial resistance problem.

Occurrence of Aeromonas spp. Resistant to Some Selected Antibiotics Isolated from Farmed Clarias gariepinus

Background: One of the major causes of disease in Clarias gariepinus is Aeromonas spp. which has been linked to significant economic losses and poses a risk to public health. Purpose: The prevalence and heterogeneity of Aeromonas species isolated from Clarias gariepinus cultured in concrete tanks, as well as the antibiogram and multiple antibiotic resistance index, were examined. Methods: In this study, using culture, biochemical characterization, and Microbact 24E kit, Aeromonas species isolates were confirmed. The Kirby Bauer disc diffusion method assessed the antibiotic susceptibility to 10 different antibiotics. Results: Four different species of Aeromonas were identified, with an overall prevalence of 55 (28.6%). Aeromonas hydrophila had the highest prevalence of 35 (18.6%), followed by 10 (5.2%) for Aeromonas caviae, then 5 (2.6 %) for Aeromonas veronii biovar sobria, and Aeromonas veronii biovar veronii, respectively. The Aeromonas species exhibited high resistance to amoxicillin, ampicillin, colistin sulphate, oxytetracycline, trimethoprim/sulphamethoxazole, and penicillin, with varied patterns of resistance, and the multiple antibiotic resistance (MAR) index values ranged between 0.10 and 0.80. Conclusion: Several antibiotic-resistant Aeromonas species were linked to the widespread emergence of antimicrobial resistance. As a result, it is crucial to regulate the use of antibiotics in fish farms and to ensure that biosecurity and preventive management strategies are applied effectively.

Helicobacter pylori Strains Isolated from Raw Poultry Meat in the Shahrekord Region, Iran: Frequency and Molecular Characteristics

Even though Helicobacter pylori (H. pylori) is a serious pathogen, its origin is unknown. Poultry (chicken, turkey, quail, goose, and ostrich) is consumed as a regular protein source by many people across the world; therefore, sanitary ways of delivering poultry for food are important for global health. As a result, the distribution of the virulence genes cagA, vacA, babA2, oipA, and iceA in H. pylori isolates in poultry meat, as well as their antibacterial resistance, was investigated. A Wilkins Chalgren anaerobic bacterial medium was used to cultivate 320 samples of raw poultry meat. Disk diffusion and multiplex-PCR were used to investigate both antimicrobial resistance and genotyping patterns. H. pylori was found in 20 of 320 (6.25 %) raw chicken meat samples. The highest incidence of H. pylori was found in chicken raw meat (15%), whereas no isolate was recovered from goose or quail raw meat (0.00%). Resistance to ampicillin (85%), tetracycline (85%), and amoxicillin (75%) were the most commonly detected in the tested H. pylori isolates. The percentage of H. pylori isolates with a multiple antibiotic resistance (MAR) index value of more than 0.2 was 17/20 (85%). The most prevalent genotypes detected were VacA (75%), m1a (75%), s2 (70%) and m2 (65%), and cagA (60%). The most typically detected genotype patterns were s1am1a (45 %), s2m1a (45 %), and s2 m2 (30%). babA2, oipA+, and oipA- genotypes were found in 40%, 30%, and 30% of the population, respectively. In summary, fresh poultry meat was polluted by H. pylori, with the babA2, vacA, and cagA genotypes being more prevalent. The simultaneous occurrence of vacA, cagA, iceA, oipA, and babA2 genotypes in antibiotic-resistant H. pylori bacteria raises a serious public health concern regarding the consumption of raw poultry. Future research should evaluate antimicrobial resistance among H. pylori isolates in Iran.

The diagnostic value of Doppler Resistive Index in the differential diagnosis of focal liver lesions.

To investigate the diagnostic value of resistance index (RI) in differentiating focal liver lesions. In this retrospective study, a total of 576 patients with histologically confirmed focal liver lesions were included. Each patient underwent B-mode ultrasound examination and color Doppler ultrasound examination. The RI values of different focal liver lesions were recorded and compared. The mean RI value of benign lesions was significantly lower than that of malignant lesions (0.54 ± 0.10 vs. 0.71 ± 0.12) (p <0.05). In malignant lesions, the RI value of intrahepatic cholangiocarcinoma was significantly lower than that of hepatocellular carcinoma lesions. Furthermore, in hepatocellular carcinoma lesions, the RI of large lesions (group 4: >10 cm) was significantly lower than that of small lesions (group 1: ≤2 cm, group 2: 2-5 cm) (p <0.05). Taken RI of 0.615 as a cutoff value to differentiate malignant and benign lesions, the sensitivity, specificity, positive predictive value and negative predictive value were 82.80%, 81.00%, 81.34% and 82.48%, respectively. Color Doppler ultrasound examination is a valuable imaging method in detecting blood flow signal within liver lesions. The RI parameter should be helpful in differentiating malignant and benign liver tumors.

Molecular mechanism of resistance to mesosulfuron-methyl in shortawn foxtail (Alopecurus aequalis) from China

AbstractShortawn foxtail (Alopecurus aequalis Sobol.) is an obligate wetland plant that is widely distributed throughout Europe, temperate Asia, and North America. In China, it is widespread in the middle and lower reaches of the Yangtze River as a noxious weed in winter cropping fields with a rice (Oryza sativa L.) rotation. The acetolactate synthase (ALS)-inhibiting herbicide mesosulfuron-methyl has been widely used to control annual grass and broadleaf weeds, including A. aequalis, in wheat (Triticum aestivum L.) fields, leading to the selection of herbicide-resistant weeds. In this study, an A. aequalis population, AHFT-4, that survived mesosulfuron-methyl at the field-recommended rate (9 g ai ha−1) was collected in Anhui Province. Single-dose testing confirmed that the suspected resistant AHFT-4 had evolved resistance to mesosulfuron-methyl. Target gene sequencing revealed a resistance mutation of Pro-197-Ala in ALS1 of the resistant plants, and a derived cleaved amplified polymorphic sequence marker was developed to specifically detect the mutation. A relative expression assay showed no significant difference in ALS expression between AHFT-4 and a susceptible population without or with mesosulfuron-methyl treatment. Whole-plant dose–response bioassays indicated that AHFT-4 had evolved broad-spectrum cross-resistance to ALS-inhibiting herbicides of all five chemical families tested, with GR50 resistance index (RI) values ranging from 21 to 206. However, it remained susceptible to the photosystem II inhibitor isoproturon. Pretreatment with the cytochrome P450 inhibitor malathion or the glutathione S-transferase inhibitor 4-chloro-7-nitrobenzoxadiazole had no significant effects on the resistance of AHFT-4 to mesosulfuron-methyl. To our knowledge, this study reports for the first time the ALS gene Pro-197-Ala substitution conferring broad-spectrum cross-resistance to ALS-inhibiting herbicides in A. aequalis.

Mutation site identification confer glyphosate resistance in goosegrass (Eleusine indica L. Gaertn) from Jonggol, Bogor, Indonesia

Glyphosate resistance is a serious problem in weed control, especially in oil palm plantations. However, evaluation of suspected resistant weeds such as Eleusine indica L. Gaertn at the gene level is still scarce in Indonesia. Here, target-site resistance to glyphosate of the EPSPS gene was evaluated. The objective of this study was to identify glyphosate resistance caused by mutation points in goosegrass biotypes from oil palm plantation in Jonggol, West Java, Indonesia. Bio-assay analysis was carried out by planting goosegrass in pots. Glyphosate was applicated using eight-level, namely 0, 0.125x, 0.25x, 0.5x, x, 2x, 4x, and 8x, where x was the recommended dose (972 g ha-1) for three replications. Weed damage was evaluated from plant biomass and then regression analysis was performed to obtain the LD50 and resistance index. The E. indica from block V had a reduced sensitivity status with 2.343 value of resistance index, and those from Block II biotype had a sensitive status with 1.588 resistance index. Alignment of the EPSPS gene showed no mutation was observed at two target-points, indicating that increasing resistance of E. indica in the study site could be controlled by other factors. Nevertheless, E. indica of block V biotype had a resistance potential due to the highest LD50. It is necessary to evaluate further the possibility of mutation in other target-points of the EPSPS gene.&#x0D; Keywords: bio-assay; EPSPS; LD50; resistance index; sequencing; target-site resistance

Acute Effects of a Maximal Cardiopulmonary Exercise Test on Cardiac Hemodynamic and Cerebrovascular Response and Their Relationship with Cognitive Performance in Individuals with Type 2 Diabetes.

Cardiovascular and cerebrovascular diseases are prevalent in individuals with type 2 diabetes (T2D). Among people with T2D aged over 70 years, up to 45% might have cognitive dysfunction. Cardiorespiratory fitness (V˙O2max) correlates with cognitive performances in healthy younger and older adults, and individuals with cardiovascular diseases (CVD). The relationship between cognitive performances, V˙O2max, cardiac output and cerebral oxygenation/perfusion responses during exercise has not been studied in patients with T2D. Studying cardiac hemodynamics and cerebrovascular responses during a maximal cardiopulmonary exercise test (CPET) and during the recovery phase, as well as studying their relationship with cognitive performances could be useful to detect patients at greater risk of future cognitive impairment. Purposes: (1) to compare cerebral oxygenation/perfusion during a CPET and during its post-exercise period (recovery); (2) to compare cognitive performances in patients with T2D to those in healthy controls; and (3) to examine if V˙O2max, maximal cardiac output and cerebral oxygenation/perfusion are associated with cognitive function in individuals with T2D and healthy controls. Nineteen patients with T2D (61.9 ± 7 years old) and 22 healthy controls (HC) (61.8 ± 10 years old) were evaluated on the following: a CPET test with impedance cardiography and cerebral oxygenation/perfusion using a near-infrared spectroscopy. Prior to the CPET, the cognitive performance assessment was performed, targeting: short-term and working memory, processing speed, executive functions, and long-term verbal memory. Patients with T2D had lower V˙O2max values compared to HC (34.5 ± 5.6 vs. 46.4 ± 7.6 mL/kg fat free mass/min; p < 0.001). Compared to HC, patients with T2D showed lower maximal cardiac index (6.27 ± 2.09 vs. 8.70 ± 1.09 L/min/m2, p < 0.05) and higher values of systemic vascular resistance index (826.21 ± 308.21 vs. 583.35 ± 90.36 Dyn·s/cm5·m2) and systolic blood pressure at maximal exercise (204.94 ± 26.21 vs. 183.61 ± 19.09 mmHg, p = 0.005). Cerebral HHb during the 1st and 2nd min of recovery was significantly higher in HC compared to T2D (p < 0.05). Executive functions performance (Z score) was significantly lower in patients with T2D compared to HC (-0.18 ± 0.7 vs. -0.40 ± 0.60, p = 0.016). Processing speed, working and verbal memory performances were similar in both groups. Brain tHb during exercise and recovery (-0.50, -0.68, p < 0.05), and O2Hb during recovery (-0.68, p < 0.05) only negatively correlated with executive functions performance in patients with T2D (lower tHb values associated with longer response times, indicating a lower performance). In addition to reduced V˙O2max, cardiac index and elevated vascular resistance, patients with T2D showed reduced cerebral hemoglobin (O2Hb and HHb) during early recovery (0-2 min) after the CPET, and lower performances in executive functions compared to healthy controls. Cerebrovascular responses to the CPET and during the recovery phase could be a biological marker of cognitive impairment in T2D.

Enhanced Herbicide Metabolism and Target-Site Mutations Confer Multiple Resistance to Fomesafen and Nicosulfuron in Amaranthus retroflexus L.

Amaranthus retroflexus L. is a highly competitive broadleaf weed of corn-soybean rotation in northeastern China. In recent years, the herbicide(s) resistance evolution has been threatening its effective management in crop fields. One resistant A. retroflexus (HW-01) population that survived the protoporphyrinogen oxidase (PPO) inhibitor fomesafen and acetolactate synthase (ALS) inhibitor nicosulfuron applied at their field-recommended rate was collected from a soybean field in Wudalianchi City, Heilongjiang Province. This study aimed to investigate the resistance mechanisms of fomesafen and nicosulfuron and determine the resistance profile of HW-01 to other herbicides. Whole plant dose-response bioassays revealed that HW-01 had evolved resistance to fomesafen (50.7-fold) and nicosulfuron (5.2-fold). Gene sequencing showed that the HW-01 population has a mutation in PPX2 (Arg-128-Gly) and a rare mutation in ALS (Ala-205-Val, eight/twenty mutations/total plants). In vitro enzyme activity assays showed that ALS extracted from the HW-01 plants was less sensitive to nicosulfuron (3.2-fold) than ST-1 plants. Pre-treatment with the cytochrome P450 inhibitors malathion, piperonyl butoxide (PBO), 3-amino-1,2,4-triazole (amitrole), and the GSTs inhibitor 4-chloro-7-nitrobenzofurazan (NBD-Cl) significantly increased fomesafen and nicosulfuron sensitivity in the HW-01 population compared with that of the sensitive (S) population ST-1. Moreover, the rapid fomesafen and nicosulfuron metabolism in the HW-01 plants was also confirmed via HPLC-MS/MS analysis. Furthermore, the HW-01 population showed multiple resistance (MR) to PPO, ALS, and PSII inhibitors, with resistance index (RI) values ranging from 3.8 to 9.6. This study confirmed MR to PPO-, ALS-, and PSII-inhibiting herbicides in the A. retroflexus population HW-01, as well as confirming that the cytochrome P450- and GST-based herbicide metabolic along with TSR mechanisms contribute to their multiple resistance to fomesafen and nicosulfuron.

Periodontitis is associated with subclinical cerebral and carotid atherosclerosis in hypertensive patients: A cross-sectional study

ObjectiveTo examine the relationship between periodontitis and subclinical intracranial atherosclerosis. The association of periodontitis with preclinical markers of atherosclerosis in other vascular territories was also explored.Material and methodsThis was a cross-sectional study where 97 elderly subjects with a previous history of hypertension received an ultrasonographic evaluation to assess subclinical atherosclerosis in different vascular territories: (1) cerebral [pulsatility (PI) and resistance index (RI) of the middle cerebral artery], (2) carotid [intima-media thickness (IMT)], and (3) peripheral [ankle-brachial index (ABI)]. Additionally, participants underwent a full-mouth periodontal assessment together with blood sample collection to determine levels of inflammatory biomarkers (leukocytes, fibrinogen, and erythrocyte sedimentation rate), lipid fractions (total cholesterol and high- and low-density lipoprotein), and glucose.ResultsSixty-one individuals had periodontitis. Compared to subjects without periodontitis, those with periodontitis showed higher values of PI (1.24 ± 0.29 vs 1.01 ± 0.16), RI (0.70 ± 0.14 vs 0.60 ± 0.06), and IMT (0.94 ± 0.15 vs 0.79 ± 0.15) (all p < 0.001). No statistically significant differences were found neither for ABI or for other clinical and biochemical parameters. An independent association was found between periodontitis and increased intracranial atherosclerosis (ORadjusted = 10.16; 95% CI: 3.14–32.90, p < 0.001) and to a lesser extent with thicker carotid IMT (ORadjusted = 4.10; 95% CI: 1.61–10.48, p = 0.003).ConclusionsPeriodontitis is associated with subclinical atherosclerosis in both intracranial and carotid arteries in elderly subjects with hypertension.Clinical relevanceThe association of periodontitis with intracranial atherosclerosis implies that periodontitis patients might have greater chances to develop ischemic stroke in the future.

Value of hepatic artery resistive index in evaluation of liver fibrosis related to non-alcoholic fatty liver diseases

Value of hepatic artery resistive index in evaluation of liver fibrosis related to non-alcoholic fatty liver diseases

Resistance and resilience of soil biological indicators: A case study with multi-walled carbon nanotube

Soil ecosystem is experiencing stresses due to climate change, and soil inhabitants try to demonstrate their inherent resistance and resilience against those stresses. Application of nanomaterials as agricultural inputs could bring shifts in resistance and resilience patterns of soil microbes and associated enzymes, especially under short-term heat stress. With this background, the impacts of multi-walled carbon nanotube (MWCNT) on the resistance and resilience of soil biological indicators were evaluated. An incubation experiment was conducted with varied MWCNT concentrations (0, 50, 100, 250, and 500 mg kg-1 soil) for 90 d after 24-h heat stress at 48 ± 2 °C to assess the impacts of MWCNT on soil enzyme activities and microbial populations vis-à-vis their resistance and resilience indices under short-term exposure to heat stress. Enzyme activities were reduced after exposure to heat stress. Resistance indices of enzyme activities were enhanced by MWCNT application on day 1 after heat stress, whereas there was no recovery of enzyme activities after 90-d incubation. Like soil enzyme activities, resistance index values of soil microbial populations followed the similar trend and were improved by MWCNT application. Multi-walled carbon nanotube has the potential to improve resistance indices of soil enzyme activities and microbial populations under heat stress, although they could not recover to their original state during periodical incubation after heat stress. This study helps to understand the relative changes of biological indicators under MWCNT and their ability to withstand heat stress.

Color doppler ultrasound analysis of pathological myopia induced changes in retrobulbar blood flow and its relationship with characteristic changes in myopia.

To analyze changes in retrobulbar blood flow in patients with pathological myopia using color doppler ultrasound (CDU), and to explore the relationship of these changes with the characteristic changes resulting from myopia. One hundred and twenty patients who met the selection criteria in the ophthalmology department of He Eye Specialist Hospital from May 2020 to May 2022 were included in this study. Patients with normal vision (n=40) were considered Group-A, patients with low and moderate myopia (n=40) were considered Group-B, and patients with pathological myopia (n=40) were considered Group-C. All three groups underwent ultrasonography. The peak systolic blood flow velocity (PSV), end-diastolic blood flow velocity (EDV), and resistance index (RI) of the ophthalmic artery, central retinal artery, and posterior ciliary artery were recorded and compared, and the characteristics of these parameters and myopia severity were analyzed. Pathological myopia resulted in significantly lower PSV and EDV of the ophthalmic artery, central retinal artery and posterior ciliary artery and higher RI values than patients with normal vision and low/moderate myopia (P<0.05). Pearson correlation analysis showed that retrobulbar blood flow changes were significantly correlated with age, eye axis, best corrected visual acuity, and retinal choroidal atrophy. CDU can objectively evaluate the retrobulbar blood flow changes in pathological myopia, and such blood flow changes are significantly correlated with the characteristic changes of myopia.

Changes in cerebral blood flow parameters among preterm 30–34 week neonates who are initiated on kangaroo mother care - A prospective analytical observational study

BackgroundKangaroo mother care (KMC) is recommended standard of care for preterm neonates. They are vulnerable for cerebral blood flow (CBF) fluctuations linked to intraventricular hemorrhage and periventricular leukomalacia, which have implications on neurodevelopment. This study was designed to document any change in CBF in middle cerebral artery (MCA) of stabilized preterm 30–34 weeks neonates who are initiated on KMC. MethodsWe designed a prospective analytical observational study in a tertiary care neonatal unit. We enrolled 30–34 weeks preterm neonates eligible for KMC after their stabilization (n = 40). CBF was measured in supine position via right MCA Doppler through the temporal window before any KMC, after 2 h of 1st KMC session and following 24 h of 1st session. CBF was quantified in terms of pulsatility index (PI), Resistive Index (RI), peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV) and values were compared against the existing normative values. ResultsMean gestation of study population was 31.91 weeks with a mean birth weight of 1432.75 g. Median day of initiation of KMC was 7 days with mean duration of KMC on day 1 was 4.56 h. We could find statistically significant decrease in the values of PI and RI from 90th centile towards 50th centile of normative values with a mean difference of 0.22 (99 % CI 0.02–0.43, p 0.005) for PI and 0.05 (99 % CI 0.02–0.07, p = 0.000) for RI post the first session of KMC. Following 24 h of 1st KMC session, we could find a significant increase in values of PSV, EDV and MV comparing values of pre-initiation with day 2 pre-KMC but values of PI and RI were not significantly different. ConclusionCBF among 30–34 week preterm neonates tend to optimize after initiation of KMC.

Doppler-ultrasound reference values after pediatric liver transplantation: a consecutive cohort study

ObjectivesDoppler ultrasound (DUS) is the main imaging modality to evaluate vascular complications of pediatric liver transplants (LT). The current study aimed to determine reference values and their change over time.MethodsA consecutive cohort of pediatric patients undergoing an LT were retrospectively included between 2015 and 2020. Timepoints for standardized DUS were intra-operative and postoperative (day 0), days 1–7, months 1 and 3, and years 1 and 2. DUS measurements of the hepatic artery (HA), portal vein (PV), and hepatic vein(s) (HV) were included if there were no complications during 2 years follow-up. Measurements consisted of: peak systolic velocity (PSV) and resistive index (RI) for the HA, PSV for the PV, and venous pulsatility index (VPI) for the HV. Generalized estimating equations were used to analyze change over time.ResultsOne hundred twelve pediatric patients with 123 LTs were included (median age 3.3 years, interquartile range 0.7–10.1). Ninety-five HAs, 100 PVs, and 115 HVs without complications were included. Reference values for HA PSV and RI, PV PSV, and HV VPI were obtained for all timepoints (4043 included data points in total) and presented using 5th–95th percentiles and threshold values. All reference values changed significantly over time (p = 0.032 to p < 0.001).ConclusionsDUS reference values of hepatic vessels in children after LT are presented, reference values change over time with specific vessel-dependent patterns. Timepoint–specific reference values improve the interpretation of DUS values and may help to better weigh their clinical significance.Key Points• Doppler ultrasound reference values of pediatric liver transplantations are not static but change over time. Applying the correct reference values for the specific timepoint may further improve the interpretation of the measurements.• The pattern of change over time of Doppler ultrasound measurements differs between the hepatic vessel and measurement; knowledge of these patterns may help radiologists to better understand normal postoperative hemodynamic changes.

Efficacy of Virtual Touch Quantification Technique for Differentiating Patients with Immunoglobulin A Nephropathy (IgAN) from Healthy Controls

Background: The virtual touch quantification (VTQ) using acoustic radiation force impulse (ARFI) is a type of ARFI technology, which has been widely used against many diseases. The sensitivity and specificity of VTQ in differentiating immunoglobulin A nephropathy (IgAN) patients from healthy controls remain unestablished. Objectives: The present study aimed to measure the VTQ values of renal parenchyma in patients with IgAN and to evaluate the efficacy of these values in distinguishing IgAN patients from healthy individuals. Patients and Methods: Ultrasound examinations were performed for the experimental and control groups. All routine ultrasound data, including the renal parenchymal thickness, renal volume, resistive index (RI) of interlobar renal arteries, and peak velocity of interlobar renal arteries, were collected. The VTQ values were measured in the middle and lower renal parenchyma using the VTQ technique. A receiver operating characteristic (ROC) curve was plotted to evaluate the efficacy of VTQ in differentiating IgAN patients from healthy individuals. Results: The VTQ values, RI values of interlobar arteries, and peak velocity of interlobar arteries were significantly different between patients with IgAN and the controls (2.14 ± 0.31 vs. 2.62 ± 0.24 m/s, 0.68 ± 0.05 vs. 0.63 ± 0.03 m/s, and 0.56 ± 0.59 vs. 0.60 ± 0.58 m/s; P &lt; 0.05 for all). The VTQ values were associated with the renal parenchymal thickness, peak flow velocity of interlobular arteries, and Lee’s grade (P &lt; 0.05 for all). The ROC curve analysis revealed that VTQ values might be used as a diagnostic method for differentiating IgAN patients (area under the curve [AUC] = 0.909) from healthy controls. Conclusion: The VTQ values significantly decreased in patients with IgAN and might play an important role in distinguishing IgAN patients from healthy individuals, with high sensitivity and specificity.

Placental perfusion using intravoxel incoherent motion MRI combined with Doppler findings in differentiating between very low birth weight infants and small for gestational age infants

IntroductionAbnormalities in placental morphology and function can lead to small for gestational age infants (SGA) and very low birth weight infants (VLBWI). In this study, we explored the value of intravoxel incoherent motion (IVIM) histogram parameters, MRI morphological parameters, and Doppler findings of the placenta in differentiating between VLBWI and SGA. MethodsThirty-three pregnant women who were diagnosed with SGA and met the inclusion criteria were enrolled in this retrospective study and divided into two groups: 22 with non-VLBWI and 11 with VLBWI. The IVIM histogram parameters (perfusion fraction (f), true diffusion coefficient (D), and pseudo-diffusion coefficient (D*)), MRI morphological parameters, and Doppler findings were compared between groups. The diagnostic efficiency was compared by receiver operating characteristic (ROC) curve analysis. ResultsThe Dmean, D90th, D*90th, fmax, and placental area of the VLBWI group were significantly lower than those of the non-VLBWI group (p < 0.05). The values of umbilical artery pulsatility index, resistance index (RI), and peak systolic velocity/end-diastolic velocity were significantly higher in the VLBWI group than in the non-VLBWI group (p < 0.05). D90th, placental area, and umbilical artery RI had the highest areas under the curve (AUCs) of the ROC curves, at 0.787, 0.785, and 0.762, respectively. A combined predictive model (D90th, placental area, and umbilical artery RI) improved the performance in differentiating between VLBWI and SGA compared with the single model (AUC = 0.942). DiscussionIVIM histogram (D90th) and MRI morphological (placental area) parameters and a Doppler finding (umbilical artery RI) may be sensitive indicators for differentiating between VLBWI and SGA.