bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cooperative NHC and Photoredox Catalyzed Radical Aminoacylation of Alkenes to Tetrahydropyridazines
Authors: Liu Wen‐Deng , Gao Jiyuan , Mo Jia‐Nan , Zhou Yuqiao , Zhao Jiannan 
Published: July 2024

AbstractTetrahydropyridazines constitute an important structural motif found in numerous natural products and pharmaceutical compounds. Herein, we report an aminoacylation reaction of alkenes that enables the synthesis of 1,4,5,6‐tetrahydropyridazines through cooperative N‐heterocyclic carbene (NHC) and photoredox catalysis. This approach involves the 6‐endo‐trig cyclization of N‐centered hydrazonyl radicals, generated via single‐electron oxidation of hydrazones, followed by a radical–radical coupling step. The mild process tolerates a wide range of common functional groups and affords a variety of tetrahydropyridazines in moderate to high yields. Preliminary investigations using chiral NHC catalysts demonstrate the potential of this protocol for asymmetric radical reactions.
Indole Nucleophile Triggers Mechanistic Divergence in Ni‐Photoredox N‐Arylation
Authors: Liang Kevin J. , Taylor Olivia R. , López Angie L. , Woo Russell J. , Bahamonde Ana 
Published: July 2024

AbstractThis study presents a Ni‐photoredox method for indole N‐arylation, broadening the range of substrates to include indoles with unprotected C3‐positions and base‐sensitive groups. Through detailed mechanistic inquiries, a Ni(I/III) mechanism was uncovered, distinct from those commonly proposed for Ni‐catalyzed amine, thiol, and alcohol arylation, as well as from the Ni(0/II/III) cycle identified for amide arylation under almost identical conditions. The key finding is the formation of a Ni(I) intermediate bearing the indole nucleophile as a ligand prior to oxidative addition, which is rare for Ni‐photoredox carbon‐heteroatom coupling and has a profound impact on the reaction kinetics and scope. The pre‐coordination of indole renders a more electron‐rich Ni(I) intermediate, which broadens the scope by enabling fast reactivity even with challenging electron‐rich aryl bromide substrates. Thus, this work highlights the often‐overlooked influence of X‐type ligands on Ni oxidative addition rates and illustrates yet another mechanistic divergence in Ni‐photoredox C‐heteroatom couplings.
Retrieval and Reuse of Surfactants From Microemulsions Enabled by a pH‐Triggered Precipitation‐Dissolution Strategy
Authors: Fan Ye , Yan Junge , Pan Jiajie , Chen Hui , Liu Xuefeng 
Published: July 2024

AbstractHow to retrieve and reuse surfactants efficiently from surfactant‐based microemulsions (MEs) has long been a problem, which is full of challenges and needs to be solved urgently. To this end, a pH‐triggered precipitation‐dissolution (PTPD) strategy is developed. The surfactant sodium 3‐(laurylamino)propane‐1‐sulfonate (LMPS) transforms into an insoluble precipitate (the inner salt of LMPS, LMP) after reaction with HCl, by which the monophasic LMPS‐based MEs demulsified entirely, giving a separable mixture of oil, water and LMP. LMP can be retrieved efficiently (~95.3 %) regardless of the ME type, and can then be conveniently restored to LMPS via reactions with NaOH. Conceptually, the retrieval of LMPS (~96.6 %), toxic benzo[a]pyrene (BaP, ~99.5 %) and a mixture of co‐surfactant n‐butanol and the oil phase n‐heptane (~97.1 %) from the sufficiently emulsified soil eluents is achievable by respectively using the PTPD strategy and distillation, wherein the soil eluents were generated from the remediation of BaP‐contaminated soil using an oil‐in‐water LMPS‐based ME as washing agent. It reveals a promising future for the PTPD strategy in the post‐processing of soil eluents containing toxic hydrophobic organic contaminants and excessive surfactants.
Design and analysis of a non‐ideal resonant switched capacitor DC‐DC converter with reduced device ratings
Authors: K Ashwin , Narayanan K Nakul , Umanand L , Reddy B Subba 
Published: July 2024

AbstractThis paper introduces a resonant switched capacitor converter (RSCC) topology that enhances the operational efficiency by utilizing devices with reduced ratings. The RSCC eliminates bulky magnetic elements, yielding increased power density, modular structure, and compact size compared with switched inductor topologies. Significantly, all the switched capacitors in the proposed converter and approximately 50% of the switching power devices are explicitly rated for the input voltage enabling its use for high‐power applications. A compact inductor is utilized for resonant operation, and the switching frequency of the converter is significantly reduced leading to reduced switching losses and improved efficiency. Zero current turn‐ON and turn‐OFF of the switching devices is achieved. Elimination of load‐side bulky capacitor using inherent output voltage ripple reduction is achieved by aligning the switching phases of the converter such that individual capacitor voltage ripple gets cancelled out. The work extensively covers the analysis of the converter in steady‐state and the effect of non‐idealities during the resonant operation. Further, a detailed design of the topology with a discussion on component selection is presented. The operation of the proposed converter is systematically analyzed through a series of simulation results generated, and the converter is further validated by developing an experimental prototype at a power of 200 W with an efficiency of 95.83%.
A PLL‐less grid‐tied three‐phase multilevel inverter with reduced device count and LCL filter
Authors: Kumar Rohit , Chaudhari Madhuri Avinash , Chaturvedi Pradyumn , Choube Sharat Chandra 
Published: July 2024

AbstractThis paper introduces a novel three‐phase grid‐tied multilevel inverter (MLI) topology that employs a basic unit per phase, yielding a symmetrical configuration capable of generating five‐level output voltage and an asymmetrical configuration producing seven‐level and nine‐level output voltages. The generalization of the proposed MLI is presented in terms of the number of modules (M) and output levels (L). A comprehensive comparative analysis of the proposed MLI topology against existing configurations is presented for both symmetric and asymmetric cases. The switching devices in the MLI are controlled using the in‐phase disposition level shift PWM (IPD‐LSPWM) technique. The synchronization of the grid‐tied MLI is addressed by considering the uncertainties in grid and load parameters at the point of common coupling (PCC). To achieve synchronization, a PLL‐less grid voltage‐ modulated direct power control (GVM‐DPC) technique is implemented. To mitigate the delay associated with PLL, a GVM‐DPC based on the stationary reference frame (SRF) is applied. This paper also includes mathematical modelling of GVM‐DPC without PLL and the design of an LCL filter. A simulation model of a 15‐kVA, three‐phase, nine‐level grid‐tied MLI is developed in MATLAB/Simulink and tested under both steady‐state and dynamic conditions. The proposed controller's performance is evaluated under the load variations and sudden changes in available power from the distributed generator (DG). Robustness is tested under adverse conditions such as voltage sag/swell at the PCC. Furthermore, the system is implemented in the OPAL‐RT OP4510 real‐time simulator, and the results are validated to confirm the effectiveness and robustness of the proposed grid‐tied MLI.
Sounding out the river: Seismic and hydroacoustic monitoring of bedload transport
Authors: Matthews Bronwyn , Naylor Mark , Sinclair Hugh , Black Andrew , Williams Richard , Cuthill Calum , Gervais Matthew , Dietze Michael , Smith Anna 
Published: July 2024

AbstractSeismological observations provide a non‐invasive and continuous means for indirectly measuring fluvial bedload transport. A significant challenge remains in independently characterising the seismic signature of bedload transport from other sources such as turbulence. We present a unique dataset from an alluvial Scottish river, combining seismic data and hydroacoustic measurements, to analyse bedload transport during three high‐flow events occurring within the same year. By studying three successive events, we assess the consistency of bedload transport thresholds in response to changing flow conditions and explore the presence of hysteresis in seismic data versus water level as an indicator of coarse bedload transport. Through the use of hydroacoustic data to independently characterise bedload transport, our findings reveal that bedload transport occurred during all three events but that the threshold for entrainment varied. These entrainment thresholds were influenced by antecedent events, with a drop of 15%–20% of the threshold flow depth following the largest of the three events. In agreement with recent studies, we also found that hysteresis in the seismic versus water level data is not sufficient for identifying and analysing bedload transport: Distinct hysteresis was only observed during the largest of the three events despite all events experiencing bedload transport as observed through the independent hydroacoustic data. Our work shows the value in combining independent datasets for long‐term monitoring of bedload transport to understand the evolution in the thresholds of bedload motion, providing crucial information for effective river and land‐use management in a changing climate with potentially impacted high‐flow events.
Heuristic estimation of river bathymetry in braided streams using digital image processing
Authors: Mancini Davide , Antoniazza Gilles , Roncoroni Matteo , Mettra François , Lane Stuart N. 
Published: July 2024

AbstractMeasurement of river bathymetry has been revolutionized by high‐resolution remote sensing that combines UAV platforms with SfM‐MVS photogrammetry. Mapping inundated and exposed areas simultaneously are possible using either two‐media refraction correction or some form of the Beer–Lambert Law to estimate water depths. If, as in turbid glacially‐fed braided streams, the bed is not visible then traditional survey techniques (e.g. differential GPS systems) are required. As an alternative, here we test whether the spatial distribution of water depths in a shallow braided stream can be modelled from basic planimetric data and used to estimate inundated zone bathymetry. We develop heuristic rules using; (1) distance from the nearest river bank; (2) total inundated width along a line tangential to the local flow direction; (3) local curvature magnitude and direction; and distance from the nearest flow (4) divergence and (5) convergence regions. We parameterize them using a sample of measured water depths in stepwise multiple linear regressions and validate them using independent data. Resulting water depth distribution maps explain between 50% and 60% of the measured water depth spatial variability when compared to independent data. After incorporating modelled water depths into digital elevation models (DEMs) of exposed areas, we show that the developed method is suitable for volumetric change calculations in both dry and inundated areas.
Orientin promotes diabetic wounds healing by suppressing ferroptosis via activation of the Nrf2/GPX4 pathway
Authors: Yang Jia‐yi , Zhuang Chen , Lin Yu‐zhe , Yu Yi‐tian , Zhou Chen‐cheng , Zhang Chao‐yang , Zhu Zi‐teng , Qian Cheng‐jie , Zhou Yi‐nan , Zheng Wen‐hao , Zhao Yu , Jin Chen , Wu Zong‐yi 
Published: July 2024

AbstractDiabetic patients often experience delayed wound healing due to impaired functioning of human umbilical vein endothelial cells (HUVECs) under high glucose (HG) conditions. This is because HG conditions trigger uncontrolled lipid peroxidation, leading to iron‐dependent ferroptosis, which is caused by glucolipotoxicity. However, natural flavonoid compound Orientin (Ori) possesses anti‐inflammatory bioactive properties and is a promising treatment for a range of diseases. The current study aimed to investigate the function and mechanism of Ori in HG‐mediated ferroptosis. A diabetic wound model was established in mice by intraperitoneal injection of streptozotocin (STZ), and HUVECs were cultured under HG to create an in vitro diabetic environment. The results demonstrated that Ori inhibited HG‐mediated ferroptosis, reducing levels of malondialdehyde (MDA), lipid peroxidation, and mitochondrial reactive oxygen species (mtROS), while increasing decreased levels of malondialdehyde, lipid peroxidation, and mitochondrial reactive oxygen species, as well as increased levels of glutathione (GSH). Ori treatment also improved the wound expression of glutathione peroxidase 4 (GPX4) and angiogenesis markers, reversing the delayed wound healing caused by diabetes mellitus (DM). Additional investigations into the mechanism revealed that Ori may stimulate the nuclear factor‐erythroid 2‐related factor 2 (Nrf2)/GPX4 signaling pathway. Silencing Nrf2 in HG‐cultured HUVECs negated the beneficial impact mediated by Ori. By stimulating the Nrf2/GPX4 signaling pathway, Ori may expedite diabetic wound healing by decreasing ferroptosis.
Reproductive health care seeking behavior in Bangladesh: A systematic literature review
Authors: Khanam Mahruba , Aktar Moonmoon , Mahamud Tareq , van Hal Guido 
Published: July 2024

AbstractBackgroundMaternal health, in terms of pregnancy and childbirth, is an important aspect of women's reproductive health and remains a public health concern in underdeveloped countries of the world. Reproductive health care seeking behavior (RHSB), in both men and women in society, is influenced by a variety of social and environmental factors that needs to be summarized.ObjectivesThis review aims to enhance understanding and perception of services in relation to RHSBs in several domains such as antenatal care (ANC), delivery care, postnatal care (PNC), and family planning (FP) services, for married women of reproductive age in Bangladesh.Search StrategyIn major databases, for example, Medline, Ovid, PubMed, Web of Science, ProQuest and Google Scholar following keywords, timeline set as 2010 up to December 30, 2022.Selection CriteriaArticles that included discussion on married women of reproductive age, and their type of care seeking behavior for reproductive health.Data Collection and AnalysisA systematic literature search was carried out and expected outcome was health care seeking behavior in the aspects of ANC, delivery care, PNC, and FP services. A data extraction form and quality appraisal form were used for data on RHSB of married women of the reproductive age group in Bangladesh and associated factors.Main ResultsA total of 245 articles were retrieved from databases; stepwise screening was done and finally 23 full‐text articles were included for analysis. Descriptive statistics were used based on the included articles for narrative synthesis. In the selected articles, 17 (73.91%) were cross‐sectional studies and more than half discussed both urban and rural women. Ante‐ and postnatal visits have proven to have positively influenced overall RHSB, as seen in Bangladesh. Grass root level workers play a major role in upgrading RHSB in women. Many factors limit rural access to mother and child health services including distance of the health facility and cost of the health service.ConclusionsIn particular, education level, women's autonomy in family decision making and distance from health service can be considered as factors influencing RHSBs in Bangladesh. Exposure to mass media and TV watching are likely to positively impact RHSB patterns for women in Bangladesh.
Pregnancy and perinatal outcomes in pregnancies following frozen embryo transfer (FET) after transcervical resection of adhesions (TCRA): A retrospective cohort study with propensity score matching analysis
Authors: Ding Kai , Li Xin , Wei Yi , Zhang Mianqiu , Ling Xiufeng , Zhao Chun 
Published: July 2024

AbstractObjectiveTo compare the pregnancy and perinatal outcomes of frozen–thawed embryo transfer (FET) in patients following transcervical resection of adhesions (TCRA) versus patients with normal uterine morphology, and to investigate the factors influencing pregnancy outcomes in patients undergoing FET after TCRA.MethodsWe retrospectively analyzed FET cycles from September 2014 to September 2023, comparing patients with normal uterine morphology to those with intrauterine adhesions (IUAs) treated with TCRA. Propensity score matching (PSM) adjusted for confounding factors. LASSO regression and multivariate logistic regression identified predictors of outcomes, which were visually represented in nomograms. Model performance was assessed using calibration curves, ROC curves, and DCA, with bootstrap method for internal validation.ResultsPost‐PSM analysis showed higher live birth rates in patients with normal uterine morphology after clinical pregnancy (75.1% vs. 61.7%, P < 0.001). No significant differences were noted in clinical pregnancy rates and perinatal outcomes between the groups. Factors influencing clinical pregnancy in FET after TCRA included basal progesterone levels, endometrial thickness, parity, infertility cause, embryo stage at transfer, number and quality of embryos transferred, IUA severity, and TCRA surgical procedures. Body mass index, basal LH levels, and day 14 HCG levels post‐embryo transfer were determinants of live birth outcome.ConclusionFET cycles following TCRA showed a lower rate of successful live births, but TCRA did not increase adverse perinatal outcome risks. Our study introduces an innovative predictive model for clinical pregnancy and live birth outcomes in patients undergoing FET following TCRA, addressing a significant void in existing research.
Effects of thalassemia minor on umbilical artery blood flow and perinatal outcomes in pregnancy: A retrospective cohort study
Authors: Zhang Li , Fan Erwen , Chen Xin , Zhuo Yeqi , Lee Yan , Yan Ruiling 
Published: July 2024

AbstractObjectiveThe aim of the present study was to compare the fetal umbilical artery blood flow parameters in the third trimester and perinatal outcomes between pregnant women with and without thalassemia minor in South China.MethodsThis was a retrospective cohort study. Doppler ultrasound was used to detect fetal umbilical artery hemodynamics in pregnant women with or without thalassemia minor during the third trimester. The main parameters assessed were umbilical artery peak systolic flow velocity/end‐diastolic flow velocity (S/D), resistance index (RI), pulsation index (PI), and relevant perinatal outcomes.ResultsThis study included 540 pregnant women, 180 with thalassemia minor and 360 being healthy controls. In the third trimester, the thalassemia minor group had higher umbilical artery S/D (P = 0.002), RI (P = 0.002), and PI (P = 0.012) than healthy pregnant women, as well as lower levels of hemoglobin (Hb) (P < 0.001) and higher ferritin levels (P < 0.001). Compared to the non‐thalassemia group, neonatal body weight in the thalassemia minor group was significantly lower (P = 0.001). Additionally, the incidence of maternal anemia (odds ratio [OR] 3.92; 95% confidence interval [CI]: 2.57–5.99, P < 0.001), low birth weight (OR 15.35; 95% CI: 1.71–137.93, P = 0.015), fetal distress (OR 2.18; 95% CI: 1.12–4.26, P = 0.023), neonatal asphyxia (OR 12.81; 95% CI: 1.40–117.33, P = 0.024), oligohydramnios (OR 18.25; 95% CI: 2.21–150.36, P = 0.007) and Apgar score <7 at 1 min after birth (OR 7.97; 95% CI: 1.53–41.54, P = 0.014) was significantly higher in the thalassemia minor group.ConclusionPregnant women with thalassemia minor have higher umbilical artery S/D, RI and PI during the third trimester and a higher risk of adverse perinatal outcomes.
Transplant renal vein thrombosis and stenosis were rescued by interventional radiology
Authors: Uchida Naoki , Miyajima Keiichiro , Yanagiswa Takafumi , Ashida Hirokazu , Kawabe Mayuko , Yamamoto Izumi , Yokoo Takashi , Kimura Takahiro , Urabe Fumihiko , Miki Jun 
Published: July 2024

IntroductionTransplant renal vein thrombosis is a serious post‐transplant complication. We report a case in which a thrombus was found in the transplant renal vein and rescued the transplanted kidney utilizing interventional radiology.Case presentationA 56‐year‐old woman underwent ABO‐compatible living donor renal transplantation due to impaired renal function caused by IgA nephropathy. On postoperative Day 13, there was a finding on transplant renal echocardiography that appeared to be an interruption of peripheral renal blood flow in diastole. Contrast‐enhanced computed tomography revealed that the vein was occluded due to the hematoma, and thrombosis was observed within, and distal contrast showed regurgitation into the collateral vessels. The stenosis was breached and balloon dilation restored progressive blood flow through interventional radiology.ConclusionAlthough open surgical thrombectomy is mainly considered for treatment for transplant renal vein thrombosis, interventional radiology might be the alternative treatment option.
VALD‐2 mitigates cisplatin‐induced acute kidney injury: Mechanistic insights into oxidative stress modulation and inflammation suppression
Authors: Zhao Xuhui , Meng Yuna , Dang Chunyan , Xue Li , Zhang Jing , Ma Shuping , Li Hongling 
Published: July 2024

AbstractThis study explores the compelling antitumor properties of VALD‐2, a synthetic Schiff base ligand known for its low toxicity. The focus is on investigating VALD‐2's protective role against cisplatin‐induced acute kidney injury (AKI) in mice, with a specific emphasis on mitigating oxidative stress and inflammation. The study involves daily intraperitoneal injections of amifostine or VALD‐2 over 7 days to establish an AKI model. Subsequently, mice were assigned to normal control, cisplatin group, cisplatin + amifostine group, and cisplatin + VALD‐2 10 mg/kg group, cisplatin + VALD‐2 20 mg/kg, and cisplatin + VALD‐2 40 mg/kg. Kidney injury is assessed through serum blood urea nitrogen (BUN) and creatinine (Cr) activity assays. Levels of inflammatory factors, tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6), in kidney tissue of mice were assessed through enzyme‐linked immunosorbent assay (ELISA). The protective effect of VALD‐2 is further examined through HE staining to observe pathological changes in kidney injury. The ultrastructural changes of renal cells and tubular epithelial cells were observed by electron microscopy under experimental conditions, indicating the effect of VALD‐2 on reversing cisplatin‐induced renal injury. The study delves into VALD‐2's protective mechanisms against cisplatin‐induced kidney injury by using western blot analysis to assess the expression levels of superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), and malondialdehyde (MDA) in kidney tissues. VALD‐2 demonstrates significant improvement in cisplatin‐induced AKI, as evidenced by increased BUN and Cr levels. It effectively protects kidney tissue from oxidative damage, enhancing SOD and GSH‐Px activities while reducing MDA levels. The study also reveals a decrease in TNF‐α and IL‐6 levels, supported by ELISA results, and histological findings confirm anti‐nephrotoxic effects. Western blot analysis shows an upregulation of antioxidant enzymes (SOD, GSH‐Px) and a reduction in MDA production. VALD‐2 emerges as a promising mitigator of cisplatin‐induced AKI, showcasing its ability to enhance oxidative stress‐related protein expression. The findings suggest VALD‐2 as a potential therapeutic agent for protecting against cisplatin‐induced kidney injury.