Analysis of hydrodynamic performance and structural parameter impacts of biplane-type otter board based on smoothed particle hydrodynamics method

In trawling fisheries, otter boards are essential tools that expand net openings and gather fish schools. This study uses the Smoothed Particle Hydrodynamics (SPH) method to create a three-dimensional numerical model for a biplane-type otter board. A scaled model is fabricated for dynamic flume experiments, validating the numerical results. Analysis with Computational Fluid Dynamics (CFD) demonstrates that the three-dimensional SPH model enhances computational accuracy over traditional CFD. A comprehensive analysis of hydrodynamic performance under various structural parameters, including camber ratio and the position of maximum camber ratio, was conducted. Results indicate that both the camber ratio and its position significantly affect the hydrodynamic performance. For maximum lift coefficient, setting the camber ratio of both boards to approximately 20% is optimal. However, for a higher lift-to-drag ratio, a 5% camber ratio for both boards is preferable. When the position of maximum camber ratio is at 10%, the lift coefficient peaks, offering the best expansion effect. Conversely, setting this position at 30% maximizes the lift-to-drag ratio, indicating better overall performance. This study provides valuable insights for optimizing otter board design in trawling fisheries

Oxytocin infusion dose-response to maintain uterine tone in obese elective cesarean patients: a randomized controlled trial

BackgroundFor cesarean delivery (CD), the 90% effective dosage (ED90) of oxytocin for a first bolus has been established. It is not yet known how much oxytocin to inject into obese women undergoing elective discectomy to keep their uterine tone (UT) appropriate. We hypothesized that patients who are overweight need a greater dose of oxytocin infusion; thus, we aimed to determine how the dose-response curve for oxytocin infusion changes following an initial 1 international unit (IU) bolus in obese women undergoing elective CD.MethodsOne hundred parturients with a body mass index (BMI) greater than 30 kg/m2 were randomly assigned to receive an infusion rate of 14, 18, 22, or 26 IU/h of oxytocin. When the uterine palpation is as hard as touching the forehead or tip of the nose, it is considered sufficient UT according to the criteria used by obstetricians. The median effective dose (ED50) and ED90 values were determined using probit analysis.ResultsWe found the ED50 and ED90 values for the infusion dose of oxytocin were around 11.0 IU/h and 19.1 IU/h, respectively. Each group had a different number of parturients who needed rescued oxytocin: 14 IU/h for six, 18 IU/h for three, one for 22 IU/h, and none for 26 IU/h. The correlation between the frequency of rescued oxytocin administration and the amount of oxytocin infusion needed to avoid uterine atony was statistically significant (p = 0.02).ConclusionThe present research showed that the most effective dosage of oxytocin infusion for obese parturients undergoing elective CD is 19.1 IU/h, following an initial loading dose of 1 IU. Patients with obesity should receive a greater dosage of prophylactic oxytocin, and further studies comparing patients with and without obesity (with higher BMI) are required.Clinical Trial Registrationhttps://www.chictr.org.cn/showproj.html?proj=159951, identifier ChiCTR2200059582

The relationship between psychological capital, stress, micro-learning environment, and professional identity in nursing interns: a structural equation modeling study

BackgroundNursing interns play a crucial role in shaping the future nursing workforce, as their professional identity is closely linked to workplace retention rates and patient outcomes. Thus, investigating the factors that influence nursing interns' professional identity is important.ObjectiveTo evaluate the relationship between psychological capital, stress, micro-learning environment, and professional identity among nursing interns.MethodsThis was a cross-sectional study. The sample consisted of 388 nursing interns from 8 comprehensive teaching hospitals across five cities in Hubei Province between March and April 2024. Data were collected using a Descriptive Information Questionnaire, the Psychological Capital Questionnaire, the Student Nurse Stress Index scale, the Healthcare Education Micro Learning Environment Measure, and the Professional Identity Scale. The structural equation model was applied to explore the influencing factors of nursing interns' professional identity.ResultsThe mean total score for professional identity was 35.57 ± 7.47. Psychological capital positively influenced professional identity directly (β = 0.16, P < 0.01), while stress as measured using the student nurse stress index had a negative impact (β = −0.20, P < 0.01). High scores on the healthcare education micro-learning environment measure positively contributed to the development of professional identity (β = 0.69, P < 0.001). Furthermore, psychological capital was identified as a mediator in the association between the healthcare education micro learning environment and professional identity, as well as between the student nurse stress index scores and professional identity.ConclusionThe study suggests that a higher level of psychological capital, low stress levels, and a satisfied micro-learning environment are essential in fostering professional identity among nursing interns. It recommends collaboration between nursing schools and clinical departments to enhance nursing interns' psychological capital and stress management skills, creating a positive and safe working environment, thereby fostering professional identity among nursing interns

Hepatitis B and Hepatitis C Seroprevalence in Children Receiving Antiretroviral Therapy for Human Immunodeficiency Virus-1 Infection in China, 2005–2009

Coinfection of hepatitis B virus (HBV) or hepatitis C virus (HCV) may compromise pediatric antiretroviral therapy (ART) in China. In this study, we evaluated the seroprevalence of HBV and HCV in children receiving ART and associated factors

Polar-facing slopes showed stronger greening trend than equatorial-facing slopes in Tibetan plateau grasslands

The orientation of slopes in alpine zones creates microclimates, e.g. equatorial-facing slopes (EFSs) are generally drier and warmer than are polar-facing slopes (PFSs). The vegetation growing in these microhabitats responds divergently to climatic warming depending on the slope orientation. We proposed a spatial metric, the greenness asymmetric index (GAI), defined as the ratio between the average normalized difference vegetation index (NDVI) on PFSs and EFSs within a given spatial window, to quantify the asymmetry of greenness across aspects. We calculated GAI for each non-overlapping 3 × 3 km2 (100 × 100 Landsat pixels) grid, and seamlessly mapped it on Tibetan Plateau (TP) grassland using NDVI time series from the Landsat-5, -7 and -8 satellites. PFSs were greener than EFSs (GAI > 1) in warm and dry areas, and EFSs were greener than PFSs (GAI < 1) in cold and wet areas. We also detected a stronger greening trend (0.0040 vs 0.0034 y−1) and a higher sensitivity of NDVI to temperature (0.031 vs 0.026 °C−1) on PFSs than EFSs, leading to a significant positive trend in GAI (0.00065 y−1, P < 0.01) in the TP from 1991 to 2020. Our results suggest that global warming exacerbated the greenness asymmetry associated with the slope orientation: PFSs are more sensitive to warming and have been greening at a faster rate than EFSs. The gradient of EFSs and PFSs provided a “natural laboratory” to study interaction of water and temperature limitations on vegetation growth. Our study is the first to detect the effect of aspect on the greening trend in the TP. Future research needs to clarify the full biotic and abiotic determinants for this spatial and temporal asymmetry of greenness across aspects with the support of extensive field measurements and refined high-resolution NDVI products.This study was funded by the National Natural Science Foundation of China 42271323 and 41971282, the Sichuan Science and Technology Program 2021JDJQ0007, the Spanish Government project TED2021-132627B-I00 funded by the Spanish MCIN, AEI/10.13039/501100011033 and the European Union NextGenerationEU/PRTR, the Fundación Ramón Areces project CIVP20A6621 and the Catalan government project SGR2021-1333.N

Isothiocyanates induce oxidative stress and suppress the metastasis potential of human non-small cell lung cancer cells

<p>Abstract</p> <p>Background</p> <p>Isothiocyanates are natural compounds found in consumable cruciferous vegetables. They have been shown to inhibit chemical carcinogenesis by a wide variety of chemical carcinogens in animal models. Recent studies have also shown that isothiocyanates have antitumor activity, inhibiting the growth of several types of cultured human cancer cells. Our previous study showed that PEITC inhibited human leukemia cells growth by inducing apoptosis. However, the effect of isothiocyanates on lung cancer cell metastasis has not been studied. In the present study, we investigated the inhibitory effects of BITC and PEITC on metastatic potential of highly metastatic human lung cancer L9981 cells.</p> <p>Methods</p> <p>Cell migration and invasion were measured by wound healing assay and transwell chemotaxis assay. Expression of metastasis-related genes was assessed by quantitative RT-PCR and Western blotting. The mechanisms of action were evaluated by flow cytometry, reporter assay and Western blotting.</p> <p>Results</p> <p>Our data showed that both BITC and PEITC inhibited L9981 cell growth in a dose-dependent manner, the IC50 values were 5.0 and 9.7 μM, respectively. Cell migrations were reduced to 8.1% and 16.5% of control, respectively; and cell invasions were reduced to 2.7% and 7.3% of control, respectively. Metastasis-related genes MMP-2, Twist and β-catenin were also modulated. BITC and PEITC inhibited cell survival signaling molecules Akt and NFκB activation. Moreover, BITC and PEITC increased ROS generation and caused GSH depletion. Pretreatment with NAC blocked BITC and PEITC induced ROS elevation and NFκB inhibition.</p> <p>Conclusion</p> <p>Our results indicated that BITC and PEITC suppress lung cancer cell metastasis potential by modulation of metastasis-related gene expression, inhibition of Akt/NFκB pathway. Induction of oxidative stress may play an important role.</p

Phase II trial of AKT inhibitor MK-2206 in patients with advanced breast cancer who have tumors with PIK3CA or AKT mutations, and/or PTEN loss/PTEN mutation

Background The PI3K/AKT pathway is activated through PIK3CA or AKT1 mutations and PTEN loss in breast cancer. We conducted a phase II trial with an allosteric AKT inhibitor MK-2206 in patients with advanced breast cancer who had tumors with PIK3CA/AKT1 mutations and/or PTEN loss/mutation. Methods The primary endpoint was objective response rate (ORR). Secondary endpoints were 6-month progression-free survival (6 m PFS), predictive and pharmacodynamic markers, safety, and tolerability. Patients had pre-treatment and on-treatment biopsies as well as collection of peripheral blood mononuclear cells (PBMC) and platelet-rich plasma (PRP). Next-generation sequencing, immunohistochemistry, and reverse phase protein arrays (RPPA) were performed. Results Twenty-seven patients received MK-2206. Eighteen patients were enrolled into the PIK3CA/AKT1 mutation arm (cohort A): 13 had PIK3CA mutations, four had AKT1 mutations, and one had a PIK3CA mutation as well as PTEN loss. ORR and 6 m PFS were both 5.6% (1/18), with one patient with HR+ breast cancer and a PIK3CA E542K mutation experiencing a partial response (on treatment for 36 weeks). Nine patients were enrolled on the PTEN loss/mutation arm (cohort B). ORR was 0% and 6 m PFS was 11% (1/9), observed in a patient with triple-negative breast cancer and PTEN loss. The study was stopped early due to futility. The most common adverse events were fatigue (48%) and rash (44%). On pre-treatment biopsy, PIK3CA and AKT1 mutation status was concordant with archival tissue testing. However, two patients with PTEN loss based on archival testing had PTEN expression on the pre-treatment biopsy. MK-2206 treatment was associated with a significant decline in pAKT S473 and pAKT T308 and PI3K activation score in PBMC and PRPs, but not in tumor biopsies. By IHC, there was no significant decrease in median pAKT S473 or Ki-67 staining, but a drop was observed in both responders. Conclusions MK-2206 monotherapy had limited clinical activity in advanced breast cancer patients selected for PIK3CA/AKT1 or PTEN mutations or PTEN loss. This may, in part, be due to inadequate target inhibition at tolerable doses in heavily pre-treated patients with pathway activation, as well as tumor heterogeneity and evolution in markers such as PTEN conferring challenges in patient selection. Trial registration ClinicalTrials.gov, NCT01277757 . Registered 13 January 2011