基于Doehlert Matrix的全贯流泵装置定转子进出流间隙优化设计

全贯流泵是一种新型的机电-水泵一体式贯流泵,然而其在运行时存在定转子间隙回流,扰乱了叶轮内的流场分布,导致泵装置产生能量损失、压力波动和噪声等问题,影响泵站的正常运行。通过数值模拟和模型试验研究全贯流泵装置定转子间隙流的水力特性,结合Doehlert Matrix设计-响应面优化法对其定转子进、出流间隙结构进行优化设计,揭示全贯流泵装置定转子进、出流间隙结构对泵装置性能的影响机理,并得到最终优化的折角式定转子进、出流间隙结构方案为:外侧延伸段长度t1为4.921r,外侧收缩段长度x1为0.624r,内侧延伸段长度t2为3.655r,内侧收缩段长度x2为1.6r(r为定转子间隙宽度),使得全贯流泵装置扬程和效率分别提升约10.3%和5.2%。

Clinical nursing value of predictive nursing in reducing complications of pregnant women undergoing short-term massive blood transfusion during cesarean section

BACKGROUND Cesarean hemorrhage is one of the serious complications,and short-term massive blood transfusion can easily cause postoperative infection and physical stress response.However,predictive nursing intervention has important clinical significance for it.AIM To explore the effect of predictive nursing intervention on the stress response and complications of women undergoing short-term mass blood transfusion during cesarean section(CS).METHODS A clinical medical record of 100 pregnant women undergoing rapid mass blood transfusion during sections from June 2019 to June 2021.According to the different nursing methods,patients divided into control group(n=50)and observation group(n=50).Among them,the control group implemented routine nursing,and the observation group implemented predictive nursing intervention based on the control group.Moreover,compared the differences in stress res-ponse,complications,and pain scores before and after the nursing of pregnant women undergoing rapid mass blood transfusion during CS.RESULTS The anxiety and depression scores of pregnant women in the two groups were significantly improved after nursing,and the psychological stress response of the observation group was significantly lower than that of the control group(P<0.05).The heart rate and mean arterial pressure(MAP)of the observation group during delivery were lower than those of the control group,and the MAP at the end of delivery was lower than that of the control group(P<0.05).Moreover,different pain scores improved significantly in both groups,with the observation group considerably less than the control group(P<0.05).After nursing,complications such as skin rash,urinary retention,chills,diarrhea,and anaphylactic shock in the observation group were 18%,which significantly higher than in the control group(4%)(P<0.05).CONCLUSION Predictive nursing intervention can effectively relieve the pain,reduce the incidence of complications,improve mood and stress response,and serve as a reference value for the nursing of women undergoing rapid mass transfusion during CS.

Amino-functionalized UiO-66-doped mixed matrix membranes with high permeation performance and fouling resistance

For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then adding amino-functionalized UiO-66-NH_(2)(Am-UiO-66-NH_(2)).Aminofunctionalization of UiO-66 was accomplished by melamine,followed by an amidation reaction to immobilize Am-UiO-66-NH_(2),which was immobilized on the surface of the membrane as well as in the pore channels,which enhanced the hydrophilicity of the membrane surface while increasing the negative potential of the membrane surface.This nanoparticle-loaded ultrafiltration membrane has good permeation performance,with a pure water flux of up to 482.3 L·m^(-2)·h^(-1) for C-SPAEKS/AmUiO-66-NH_(2) and a retention rate of up to 98.7%for bovine serum albumin(BSA)-contaminated solutions.Meanwhile,after several hydrophilic modifications,the flux recovery of BSA contaminants by this series of membranes increased from 56.2%to 80.55%of pure membranes.The results of ultra-filtration flux time tests performed at room temperature showed that the series of ultrafiltration membranes remained relatively stable over a test time of 300 min.Thus,the newly developed mixed matrix membrane showed potential for high efficiency and stability in wastewater treatment containing bovine serum proteins.

Proper interpretation of sectional analysis results

Displacement control algorithms commonly used to evaluate axial force-bending moment(PM)diagrams may lead to incorrect interpretations of the strength envelopes for asymmetric sections.This paper aims to offer valuable insights by comparing existing displacement control algorithms with a newly proposed force control algorithm.The main focus is on the PM diagrams of three example sections that exhibit varying degrees of asymmetry.The comparative study indicates that conventional displacement control algorithms inevitably introduce non-zero out-of-plane bending moments.The reported PM diagram in such cases erroneously neglects the out-of-plane moment and fails to represent the strength envelope accurately.This oversight results in significant and unconservative errors when verifying the strength of asymmetric sections.

Recent progress in ternary mixed matrix membranes for CO_(2) separation

Mixed matrix membranes(MMMs)could combine the advantages of both polymeric membranes and porousfillers,making them an effective alternative to conventional polymer membranes.However,interfacial incompatibility issues,such as the presence of interfacial voids,hardening of polymer chains,and blockage of micropores by polymers between common MMMsfillers and the polymer matrix,currently limit the gas sep-aration performance of MMMs.Ternary phase MMMs(consisting of afiller,an additive,and a matrix)made by adding a third compound,usually functionalized additives,can overcome the structural problems of binary phase MMMs and positively impact membrane separation performance.This review introduces the structure and fabrication processes for ternary MMMs,categorizes various nanofillers and the third component,and summarizes and analyzes in detail the CO_(2) separation performance of newly developed ternary MMMs based on both rubbery and glassy polymers.Based on this separation data,the challenges of ternary MMMs are also discussed.Finally,future directions for ternary MMMs are proposed.

High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells

BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral integrity.AIM To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral defects.METHODS We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM deposition.Decellularized sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the controls.Three weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee joints.RESULTS The defects were successfully repaired by applying the ECM-sheets.The highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem cells.CONCLUSION Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship.

Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMS techniques

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great significance.To address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMS)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion reactors.At the China Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He reaction.The^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMS at the Institute of Geochemistry,Chinese Academy of Sciences.The neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb reaction.The measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature data.The newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental values.The obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYS−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

Associations of Perchlorate,Nitrate,and Thiocyanate with Sex Hormones among Children:A Nationally Representative Cross-sectional Study in U.S.

Nitrates,thiocyanates,and perchlorates are ubiquitous in the environment and can be introduced to the public through various dietary and environmental sources.Nitrates,thiocyanates,and perchlorates mainly affect health via the same mechanism.These toxins may act as endocrine disrupters and can result in decreased levels of thyroid hormones^([1]).

Adjuvant Rectal Diclofenac for Post Operative Analgesia after Caesarean Section—A Randomized Controlled Study

BACKGROUND: Pain management following caesarean section still remains a challenge in our environment. Most potent analgesics are either not readily available or expensive. Diclofenac suppository is an NSAID that can be used for postoperative analgesia. It is available and affordable. OBJECTIVE: To compare the efficacy and safety of combined rectal diclofenac and intramuscular pentazocine with intramuscular pentazocine alone for post operative pain control following lower segment caesarean section. METHODOLOGY: A total of 120 women who met the selection criteria scheduled for caesarean section under spinal anaesthesia with bupivacaine were randomized into two equal groups to receive either 75 mg diclofenac suppository 12 hourly for 24 hours or one anusol suppository (the placebo) 12 hourly for 24 hours. Both groups received pentazocine as primary analgesia. RESULT: The primary outcome measure is the proportion of patients with severe pain at 24 hours using the visual analogue rating scale. Secondary outcome measures are the time from surgery to ambulation, Passage of flatus, maternal satisfaction and presence of complications. Statistical analysis was done using spss version 22 and graph pad statistical package. Student T-test was used for continuous variables whereas chi square was used for categorical variables P CONCLUSION: Adjuvant rectal diclofenac is superior to pentazocine alone in the management of pain after caesarean section. Less number of patients had moderate to severe pain at 24 hours post operation. Maternal satisfaction in relation to pain management is better with diclofenac suppository. The levels of complications were comparable in both groups.

Acceptability of Caesarean Section among Pregnant Women Seeking Antenatal Care at Women and Newborn Hospital-University Teaching Hospitals, Lusaka Zambia

Caesarean section remains one of the most common obstetric and major operations performed on women during pregnancy and has contributed to improving maternal and foetal health. Consequently, significant mortality and morbidity from pregnancy and labour-related causes can be eliminated by a timely caesarean section. The acceptance of the life-saving procedure remains unsatisfactory in most sub-Saharan nations. The study aimed to assess the acceptability of caesarean section and associated factors among pregnant women seeking antenatal care at Women and Newborn Hospital-University Teaching Hospitals in Lusaka Zambia. The study utilised a quantitative cross-sectional analytical study design involving 420 pregnant women selected using systematic random sampling at Women and Newborn Hospital-University Teaching Hospitals Lusaka Zambia. Data was obtained using an Interview schedule and analysed using R software version 4.3.2. Chi-square, Fisher’s exact test, Wilcoxon rank sum test and binary logistic regression for statistical analysis at a 5% level of significance. The study found that the acceptability of Caesarean section as a mode of delivery was low (29%) among respondents at Women and Newborn Hospital-University Teaching Hospitals. This was influenced by marital status (P = 0.002), socioeconomic status (P = 0.050), parity (P = 0.004), gestation age (P = 0.008), previous history of caesarean section (P = 0.003), knowledge (P < 0.001), attitude (P < 0.001), and sociocultural beliefs (P = 0.045). Low acceptability of Caesarean section delivery is common among women at Women and Newborn Hospital-University Teaching Hospitals, despite its potential benefits for maternal and neonatal health. Socio-demographic and maternal characteristics, knowledge, attitude, perception, and socio-cultural beliefs play a major role in determining acceptability. Therefore, efforts to enhance acceptability should focus on improving knowledge, enhancing positive perceptions and attitudes, and allaying negative socio-cultural beliefs towards caesarean section.

Neurocircuit regeneration by extracellular matrix reprogramming

The brain's extracellular matrix(ECM),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functioning(Soles et al.,2023).Synthesized by neural and glial cells,the brain's ECM regulates a myriad of homeostatic cellular processes,including neuronal plasticity and firing(Miyata et al.,2012),cation buffering(Moraws ki et al.,2015),and glia-neuron interactions(Anderson et al.,2016).Considering the diversity of functions,dynamic remodeling of the brain's ECM indicates that this understudied medium is an active participant in both normal physiology and neurological diseases.

Utero-Cutaneous Fistula after Caesarean Section Delivery: Diagnosis and Management of a Rare Complication

Utero-cutaneous fistula following cesarean section is a rare occurrence. We present the case of a 34-year-old woman who presented to our department four years after her second cesarean section with a history of pain and blood discharge from a previous Pfannenstiel incision, during menstruation, with an absence of vaginal menstrual flow. Despite a prior surgical repair operation, her symptoms persisted. A pelvic MRI was done to confirm the diagnosis of utero-cutaneous fistula, and surgical management was pursued. This case report aims to contribute to the existing literature on utero-cutaneous fistula and provide insights into the diagnostic considerations and management strategies for this rare complication.

Three-dimensional crystal defect imaging by STEM depth sectioning

One of the major innovations awaiting in electron microscopy is full three-dimensional imaging at atomic resolution.Despite the success of aberration correction to deep sub-angstrom lateral resolution,spatial resolution in depth is still far from atomic resolution.In scanning transmission electron microscopy(STEM),this poor depth resolution is due to the limitation of the illumination angle.To overcome this physical limitation,it is essential to implement a next-generation aberration corrector in STEM that can significantly improve the depth resolution.This review discusses the capability of depth sectioning for three-dimensional imaging combined with large-angle illumination STEM.Furthermore,the statistical analysis approach remarkably improves the depth resolution,making it possible to achieve three-dimensional atomic resolution imaging at oxide surfaces.We will also discuss the future prospects of three-dimensional imaging at atomic resolution by STEM depth sectioning.

Polymyomectomy during Cesarean Section at the University Hospital Center of Brazzaville (Congo): About a Case and Review of the Literature

Introduction: Myomectomy during cesarean section has long been a controversial subject. The increased risk of intraoperative hemorrhage and potential hysterectomy has led many teams to contraindicate it, postponing it three to six months after delivery, thus giving more time for uterine involution, myoma shrinkage and reducing operative time and blood loss. Clinical Observation: We report the case of a polymyomectomy after use of a segmental tourniquet and bilateral ligation of the hypogastric arteries during a cesarean section for hemorrhagic placenta previa at the end of a spontaneous pregnancy of 28 weeks of amenorrhea in a 42-year-old nulliparous primigravida patient. Conclusion: Polymyomectomy during cesarean section is possible and requires knowledge of preventive hemostasis techniques and surgical experience.

Matrix Riccati Equations in Optimal Control

In this paper, the matrix Riccati equation is considered. There is no general way for solving the matrix Riccati equation despite the many fields to which it applies. While scalar Riccati equation has been studied thoroughly, matrix Riccati equation of which scalar Riccati equations is a particular case, is much less investigated. This article proposes a change of variable that allows to find explicit solution of the Matrix Riccati equation. We then apply this solution to Optimal Control.

State-selective charge exchange cross sections in collisions of highly-charged sulfur ions with helium and molecular hydrogen

The state-selective cross section data are useful for understanding and modeling the x-ray emission in celestial observations.In the present work,using the cold target recoil ion momentum spectroscopy,for the first time we investigated the state-selective single electron capture processes for S^(q+)–He and H_(2)(q=11–15)collision systems at an impact energy of q×20 keV and obtained the relative state-selective cross sections.The results indicate that only a few principal quantum states of the projectile energy level are populated in a single electron capture process.In particular,the increase of the projectile charge state leads to the population of the states with higher principal quantum numbers.It is also shown that the experimental averaged n-shell populations are reproduced well by the over-barrier model.The database is openly available in Science Data Bank at 10.57760/sciencedb.j00113.00091.

Numerical simulation of flow field deposition and erosion characteristics around bridge-road transition section

Wind-sand flow generates erosion and deposition around obstacles such as bridges and roadbeds, resulting in sand damage and endangering railway systems in sandy regions. Previous studies have mainly focused on the flow field around roadbeds, overlooking detailed examinations of sand particle erosion and deposition patterns near bridges and roadbeds. This study employs numerical simulations to analyze the influence of varying heights and wind speeds on sand deposition and erosion characteristics at different locations: the bridge-road transition section(side piers), middle piers, and roadbeds. The results show that the side piers, experience greater accumulation than the middle piers. Similarly, the leeward side of the roadbed witnesses more deposition compared to the windward side. Another finding reveals a reduced sand deposition length as the vertical profile, in alignment with the wind direction, moves further from the bridge abutments at the same clearance height. As wind speeds rise, there’s a decline in sand deposition and a marked increase in erosion around the side piers, middle piers and roadbeds. In conclusion, a bridge clearance that’s too low can cause intense sand damage near the side piers, while an extremely high roadbed may lead to extensive surface sand deposition. Hence, railway bridges in areas prone to sandy winds should strike a balance in clearance height. This research provides valuable guidelines for determining the most suitable bridge and roadbed heights in regions affected by wind and sand.

Effect of intraoperative injection of esketamine on postoperative analgesia and postoperative rehabilitation after cesarean section

BACKGROUND Following cesarean section,a significant number of women encounter moderate to severe pain.Inadequate management of acute pain post-cesarean section can have far-reaching implications,adversely impacting maternal emotional wellbeing,daily activities,breastfeeding,and neonatal care.It may also impede maternal organ function recovery,leading to escalated opioid usage,heightened risk of postpartum depression,and the development of chronic postoperative pain.Both the Chinese Enhanced Recovery After Surgery(ERAS)guidelines and the American ERAS Society guidelines consistently advocate for the adoption of multimodal analgesia protocols in post-cesarean section pain management.Esketamine,functioning as an antagonist of the N-Methyl-D-Aspartate receptor,has been validated for pain management in surgical patients and has exhibited effectiveness in depression treatment.Research has suggested that incorporating esketamine into postoperative pain management via pain pumps can lead to improvements in short-term depression and pain outcomes.This study aims to assess the efficacy and safety of administering a single dose of esketamine during cesarean section.AIM To investigate the effect of intraoperative injection of esketamine on postoperative analgesia and postoperative rehabilitation after cesarean section.METHODS A total of 315 women undergoing elective cesarean section under combined spinal-epidural anesthesia were randomized into three groups:low-dose esketamine(0.15 mg/kg),high-dose esketamine(0.25 mg/kg),and control(saline).Postoperative Visual Analog Scale(VAS)scores were recorded at 6 hours,12 hours,24 hours,and 48 hours.Edinburgh Postnatal Depression Scale(EPDS)scores were noted on 2 days,7 days and 42 days.Ramsay sedation scores were assessed at specified intervals post-injection.Postoperative adverse reactions were also recorded.RESULTS Low-dose group and high-dose group compared to control group,had significantly lower postoperative VAS pain scores at 6 hours 12 hours,and 24 hours(P<0.05),with reduced analgesic usage(P<0.05).EPDS scores and postpartum depression rates were significantly lower on 2 days and 7 days(P<0.05).No significant differences in first exhaust and defecation times were observed(P>0.05),but ambulation times were shorter(P<0.05).Ramsay scores were higher at 5 minutes,15 minutes,and upon room exit(P<0.05).Low-dose group and high-dose group had higher incidences of hallucination,lethargy,and diplopia within 2 hours(P<0.05),and with low-dose group had lower incidences of hallucination,lethargy,and diplopia than high-dose group(P<0.05).CONCLUSION Esketamine enhances analgesia and postpartum recovery;a 0.15 mg/kg dose is optimal for cesarean sections,balancing efficacy with minimized adverse effects.

Effect of Single- versus Double-Layer Uterine Closure during Caesarean Section on Niche Formation and Menstrual Irregularity

Background: The myometrium at the location of the CS (caesarean section) scars, also known as residual myometrium thickness (RMT), is larger after a double-layer uterine closure procedure than following a single-layer one. It may lessen the formation of a niche that is the myometrium’s disruption at the location of the scar of the uterus. Gynecological manifestations, obstetric problems in a future pregnancy and birth, and maybe subfertility are linked to thin RMT and a niche. Objective: To ascertain if double-layer unlocked closure of the uterus is better than single-layer one in terms of post-menstrual spotting and niche development following a first CS. Patients and Methods: In this randomized clinical study, 287 patients were evaluated for qualifying. Of all eligible individuals, 57 patients were excluded from the study based on the inclusion criteria. Results: The variation in ages, gestational age, body mass index (BMI), and cesarean section indications between the two assigned groups is statistically insignificant. However, postmenstrual spotting was statistically significantly more common in single-layer group compared to in double-group. The current study revealed ultrasound findings suggestive of niche formation was statistically significantly more common in single-layer group compared to in double-layer group. Conclusion: As evident from the current study, it demonstrates the advantages of double-layer unlocked closure of the uterus over single-layer one in terms of post-menstrual spotting and niche development following first-time cs. Thus, we deduced that fewer niches are formed, and fewer menstrual spotting occurs in the presence of double unlocked layers closure. To ascertain the impact of uterus closure method on post-operative niche development and the risk of obstetrics and gynaecological problems, further prospective trials with extended follow-up periods are required.

Efficient Clustering Network Based on Matrix Factorization

Contrastive learning is a significant research direction in the field of deep learning.However,existing data augmentation methods often lead to issues such as semantic drift in generated views while the complexity of model pre-training limits further improvement in the performance of existing methods.To address these challenges,we propose the Efficient Clustering Network based on Matrix Factorization(ECN-MF).Specifically,we design a batched low-rank Singular Value Decomposition(SVD)algorithm for data augmentation to eliminate redundant information and uncover major patterns of variation and key information in the data.Additionally,we design a Mutual Information-Enhanced Clustering Module(MI-ECM)to accelerate the training process by leveraging a simple architecture to bring samples from the same cluster closer while pushing samples from other clusters apart.Extensive experiments on six datasets demonstrate that ECN-MF exhibits more effective performance compared to state-of-the-art algorithms.