Mechanical Performance of Bio-inspired Bidirectional Corrugated Sandwich Pressure Shell Under External Hydrostatic Pressure

This paper aims to enhance the compression capacity of underwater cylindrical shells by adopting the corrugated sandwich structure of cuttlebone.The cuttlebone suffers uniaxial external compression,while underwater cylindrical shells are in a biaxial compressive stress state.To suit the biaxial compressive stress state,a novel bidirectional corrugated sandwich structure is proposed to improve the bearing capacity of cylindrical shells.The static and buckling analysis for the sandwich shell and the unstiffened cylindrical shell with the same volume-weight ratio are studied by numerical simulation.It is indicated that the proposed sandwich shell can effectively reduce the ratio between circumferential and axial stress from 2 to 1.25 and improve the critical buckling load by about 1.63 times.Numerical simulation shows that optimizing and adjusting the structural parameters could significantly improve the advantage of the sandwich shell.Then,the hydrostatic pressure tests for shell models fabricated by 3D printing are carried out.According to the experimental results,the overall failure position of the sandwich shell is at the center part of the sandwich shell.It has been found the average critical load of the proposed sandwich shell models exceeds two times that of the unstiffened shell models.Hence,the proposed bio-inspired bidirectional corrugated sandwich structure can significantly enhance the pressure resistance capability of cylindrical shells.

Effect of external magnetic field on the instability of THz plasma waves in nanoscale graphene field-effect transistors

The instability of plasma waves in the channel of field-effect transistors will cause the electromagnetic waves with THz frequency.Based on a self-consistent quantum hydrodynamic model,the instability of THz plasmas waves in the channel of graphene field-effect transistors has been investigated with external magnetic field and quantum effects.We analyzed the influence of weak magnetic fields,quantum effects,device size,and temperature on the instability of plasma waves under asymmetric boundary conditions numerically.The results show that the magnetic fields,quantum effects,and the thickness of the dielectric layer between the gate and the channel can increase the radiation frequency.Additionally,we observed that increase in temperature leads to a decrease in both oscillation frequency and instability increment.The numerical results and accompanying images obtained from our simulations provide support for the above conclusions.

Effects of vacancy and external electric field on the electronic properties of the MoSi_(2)N_(4)/graphene heterostructure

Recently,the newly synthesized septuple-atomic layer two-dimensional(2D)material MoSi_(2)N_(4)(MSN)has attracted attention worldwide.Our work delves into the effect of vacancies and external electric fields on the electronic properties of the MSN/graphene(Gr)heterostructure using first-principles calculation.We find that four types of defective structures,N-in,N-out,Si and Mo vacancy defects of monolayer MSN and MSN/Gr heterostructure are stable in air.Moreover,vacancy defects can effectively modulate the charge transfer at the interface of the MSN/Gr heterostructure as well as the work function of the pristine monolayer MSN and MSN/Gr heterostructure.Finally,the application of an external electric field enables the dynamic switching between n-type and p-type Schottky contacts.Our work may offer the possibility of exceeding the capabilities of conventional Schottky diodes based on MSN/Gr heterostructures.

Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg alloy.The AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg alloy.Refining elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-Al.At a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and net-shrinkage.With an increase in slow shot speed,the size and number of ESCs and porosities significantly reduce.In addition,the distribution of ESCs is more dispersed and the net-shrinkage disappears.The tensile property is greatly improved by adopting a higher slow shot speed.The ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

Unraveling the efficacy network: A network meta-analysis of adjuvant external beam radiation therapy methods after hepatectomy

BACKGROUND Primary liver cancer is a malignant tumor with a high recurrence rate that significantly affects patient prognosis.Postoperative adjuvant external radiation therapy(RT)has been shown to effectively prevent recurrence after liver cancer resection.However,there are multiple RT techniques available,and the differ-ential effects of these techniques in preventing postoperative liver cancer re-currence require further investigation.AIM To assess the advantages and disadvantages of various adjuvant external RT methods after liver resection based on overall survival(OS)and disease-free survival(DFS)and to determine the optimal strategy.METHODS This study involved network meta-analyses and followed the PRISMA guidelines.The data of qualified studies published before July 10,2023,were collected from PubMed,Embase,the Web of Science,and the Cochrane Library.We included relevant studies on postoperative external beam RT after liver resection that had OS and DFS as the primary endpoints.The magnitudes of the effects were determined using risk ratios with 95%confidential intervals.The results were analyzed using R software and STATA software.RESULTS A total of 12 studies,including 1265 patients with hepatocellular carcinoma(HCC)after liver resection,were included in this study.There was no significant heterogeneity in the direct paired comparisons,and there were no significant differences in the inclusion or exclusion criteria,intervention measures,or outcome indicators,meeting the assumptions of heterogeneity and transitivity.OS analysis revealed that patients who underwent stereotactic body radiotherapy(SBRT)after resection had longer OS than those who underwent intensity modulated radiotherapy(IMRT)or 3-dimensional conformal RT(3D-CRT).DFS analysis revealed that patients who underwent 3D-CRT after resection had the longest DFS.Patients who underwent IMRT after resection had longer OS than those who underwent 3D-CRT and longer DFS than those who underwent SBRT.CONCLUSION HCC patients who undergo liver cancer resection must consider distinct advantages and disadvantages when choosing between SBRT and 3D-CRT.IMRT,a RT technique that is associated with longer OS than 3D-CRT and longer DFS than SBRT,may be a preferred option.

Evidence for the Reliability and Validity of the Arabic Version of the Student Risk Screening Scale for Internalizing and Externalizing Behaviors (SRSS-IE)

School-based universal screening for behavioral/emotional risk is a necessary first step to providing services in an educational setting for students with emotional and behavioral disorders (EBDs). Psychometric properties are critical to making decisions about choosing a screening instrument. The purpose of the present study was to examine the psychometric properties of the student risk screening scale for internalizing and externalizing behaviors (SRSS-IE). Participants included 3145 students and their teachers. Item-level analyses of the current sample supported the retention of all items. The internal consistency of the SRSS items ranged from 0.83 to 0.85. Convergent validity between the SRSS-IE and a well-established screening tool, the strength and difficulties questionnaire (SDQ), was found for the total score (r = 0.70). Additionally, the results of this study demonstrate strong social validity, suggesting the SRSS-IE to be a useful and functional screening tool. We conclude that the SRSS-IE is a valid and reliable instrument for assessing the level of emotional and behavioral difficulties among elementary students.

Clinical study on the treatment of acute pancreatitis with external application of Yi-Dan Therapy based on the method of“stagnation requiring dispersion”:study protocol for a randomized controlled trial

Background:Acute pancreatitis is an unpredictable and potentially lethal disease,causing tremendous pain in patients.The initial treatment of acute pancreatitis in modern medicine is supportive,but it is generally ineffective in relieving abdominal pain and distension.Traditional Chinese medicine has been shown to be more effective in regulating the body’s homeostasis and reducing the clinical symptoms of pancreatitis.Yi-Dan ointment,derived from Dahuang-Mudan Decoction,is an effective external ointment for treating acute pancreatitis.The aim of this trial is to investigate the clinical efficacy of Yi-Dan ointment,providing a valuable complement to existing treatment options for pancreatitis.Methods:This is a randomized controlled clinical trial with two parallel groups.Patients in the control group were given basic treatment and nursing for 7 days;in the treatment group,Yi-Dan ointment was applied externally in addition to basic treatment and nursing.The main indicator is the overall efficacy,serum amylase,acute physiology and chronic health evaluationⅡscore,symptom score,inflammatory markers,and classification of computed tomography.Conclusion:The trial results will provide high-quality evidence for Yi-Dan ointment,and provide a complement to existing treatment options for pancreatitis.

Comparative Analysis of Statistical Thickness Models for the Determination of the External Specific Surface and the Surface of the Micropores of Materials: The Case of a Clay Concrete Stabilized Using Sugar Cane Molasses

In this work, four empirical models of statistical thickness, namely the models of Harkins and Jura, Hasley, Carbon Black and Jaroniec, were compared in order to determine the textural properties (external surface and surface of micropores) of a clay concrete without molasses and clay concretes stabilized with 8%, 12% and 16% molasses. The results obtained show that Hasley’s model can be used to obtain the external surfaces. However, it does not allow the surface of the micropores to be obtained, and is not suitable for the case of simple clay concrete (without molasses) and for clay concretes stabilized with molasses. The Carbon Black, Jaroniec and Harkins and Jura models can be used for clay concrete and stabilized clay concrete. However, the Carbon Black model is the most relevant for clay concrete and the Harkins and Jura model is for molasses-stabilized clay concrete. These last two models augur well for future research.

Nonlinear Pushover Analysis of the Influences on RC Footing for the External Elevator Well

In contemporary society, reducing carbon dioxide emissions and achieving sustainable development are paramount goals. One effective approach is to preserve existing RC (Reinforced Concrete) buildings rather than demolishing them for new construction. However, a significant challenge arises from the lack of elevator designs in many of these existing RC buildings. Adding an external elevator becomes crucial to solving accessibility issues, enhancing property value, and satisfying modern residential buildings using convenient requirements. However, the structural performance of external elevator wells remains understudied. This research is designed by the actual external elevator project into existing RC buildings in Jinzhong Rd, Shanghai City. Specifically, this research examines five different external elevator wells under nonlinear pushover analysis, each varying in the height of the RC (Reinforced Concrete) footing. By analyzing plastic hinge states, performance points, capacity curves, spectrum curves, layer displacement, and drift ratio, this research aims to provide a comprehensive understanding of how these structures of the external elevator well respond to seismic events. The findings are expected to serve as a valuable reference for future external elevator projects, ensuring the external elevator designs meet the seismic requirements. By emphasizing seismic resistance in the design phase, the research aims to enhance the overall safety and longevity of external elevator systems integrated into existing RC buildings.

Weak External Bisection of Some Graphs

Let G be a graph. A bipartition of G is a bipartition of V (G) with V (G) = V1 ∪ V2 and V1 ∩ V2 = ∅. If a bipartition satisfies ∥V1∣ - ∣V2∥ ≤ 1, we call it a bisection. The research in this paper is mainly based on a conjecture proposed by Bollobás and Scott. The conjecture is that every graph G has a bisection (V1, V2) such that ∀v ∈ V1, at least half minuses one of the neighbors of v are in the V2;∀v ∈ V2, at least half minuses one of the neighbors of v are in the V1. In this paper, we confirm this conjecture for some bipartite graphs, crown graphs and windmill graphs.

Gangrene of the External Genitalia at Chu-Abeche

Introduction: Gangrene of the external genitalia organs (EGO) is a medico-surgical emergency that is still very common in Third World countries. The main etiologies are urogenital, dermocutaneous and proctological. Mortality remains very high despite therapeutic advances. Our aim was to report on the epidemiological, diagnostic and therapeutic aspects of gangrene of the external genitalia, and to identify prognostic factors. Patients and Method: This was a 5-year retrospective descriptive study, from February 2016 to February 2021, of cases of gangrene of the external genitalia admitted to and treated in the Urology Department of Abeche University Hospital. Results: We collected 49 cases of gangrene of the external genitalia. The mean age of patients was 42 ± 16.81, with extremes of 20 and 81 years. The age group most concerned was between 20 and 29. The most frequent reasons for consultation were suppuration of the external genitalia and scrotal swelling. The average consultation time was 19.05 ± 16.02 days. The most common comorbidity was diabetes (35.9%). The most frequent pathological antecedents were urinary tract infections and endourethral maneuvers, reported in 40.5% and 38.7% respectively. Urogenital aetiology was predominant in 54.7%, and idiopathic in 35.9%. Lesions involved the scrotum in 60.6%, the scrotum and penis in 16.5%, and the penis alone in 5.7% of cases. Lesions extended to the perineum in 13.6% of cases, and to the abdomen in 3.6%. Vascular filling via the central venous line was performed in 58.6% of cases, and via the peripheral venous line in 41.4%. 3rd-generation cephalosporins and associated imidazoles were the most commonly used antibiotics. Necrosectomy was performed in 37 patients (73.4%), debridement combined with bypass cystostomy in 26.6% of cases. Colostomy was performed in 4% of cases. 90.8% of patients were cured and 9.2% died. The average hospital stay was 30 ± 75 days. Conclusion: The gangrene of the external genitalia is a medical and surgical emergency which has become rare in Europe, but which is still very common in the context of our practice in Chad. The severity of the disease is linked to delayed consultation and co-morbidity factors. Mortality remains very high despite therapeutic advances.

External Otitis: Epidemiological, Clinical, Etiological, and Therapeutic Aspects at the Oto-Rhino-Laryngology Department of Mamou Regional Hospital

Introduction: External otitis (OE) is an acute or chronic inflammation or infection of the external ear resulting from an imbalance in the external auditory canal secondary to microtrauma, maceration, eczema, or a foreign body in the external auditory canal. Objective: To study cases of external otitis at the Mamou Regional Hospital. Materials and Methods: This was a prospective descriptive study conducted over a period of six (6) months from July 1st to December 31st, 2016. It included all patients admitted to the ENT department of the Mamou Regional Hospital. Results: During the study period, 712 patients were admitted to the department for various pathologies, of which 103 met our selection criteria, representing a frequency of 14.46%. The mean age of the patients was 33.74 years with a range of 1 to 90 years. Males predominated in the sample, accounting for 59.22%. The vast majority of patients resided in urban areas, constituting 61.17% of the sample. In our study, all patients consulted for otalgia (100%), and over half (53.39%) for hypoacusis. We formally identified rhinitis in 66.66% of cases, while diabetes was found in only 4 patients (11.11%). Otomycosis was the most commonly identified condition (53.39%), followed by furuncles (33.98%). Ear drops containing antibiotics were administered to all patients, although 66.60% received antibiotic therapy. Conclusion: External otitis is a relatively common condition, particularly among children and the elderly. Diagnosis can be made based on pain upon traction of the pinna and pressure on the tragus.

The Discourse-Historical Approach of Identity Construction in Corporate Promotional Videos for External Publicity Image

Corporate identity construction of external publicity image is an important part of the development of enterprises.Based on Wodak’s discourse-historical approach,this study takes the text of COFCO’s English promotional video as the research object,analyzes the corporate brand image,media image,organizational image,and environmental image constructed by the enterprises from three steps:linguistic expression,discourse strategy,and theme to provide references for Chinese enterprises to enhance their international influence.

Research Progress of Traditional Chinese Medicine External Treatment for Cancer Pain

Cancer pain,as a common complication in patients with malignant tumors,is regarded as the fifth vital sign.The involvement of traditional Chinese medicine(TCM)in the treatment of malignant tumors has become a distinctive feature of oncology treatment in China.It is also an important component of cancer pain management.TCM analgesic treatments include various methods,such as internal medicine and external therapies.External analgesic therapies,in particular,are significant methods in TCM pain management and offer both local treatment and systemic regulation.These methods are simple,easy to perform,and non-invasive.They can enhance pain relief effects while reducing the difficulty of oral medication intake and avoiding adverse gastrointestinal reactions,providing new perspectives and approaches for cancer pain treatment with broad development prospects.This article provides a review of the external TCM therapies for cancer pain to share with peers in the field.

Current Research Status of Traditional Chinese Medicine External Treatment for Diarrhea Type Irritable Bowel Syndrome

Irritable bowel syndrome(IBS-D)with diarrhea is a common gastrointestinal functional disease in clinical practice,which seriously affects the quality of life of patients.Cur‐rently,Western medicine has poor therapeutic effects,while traditional Chinese medi‐cine has unique advantages in relieving IBS-D symptoms and preventing recurrence.In recent years,especially with external treatment of traditional Chinese medicine,it has become a new treatment direction in clinical practice and has achieved good therapeutic effects.This article will provide a review of recent research on the treatment of IBS-D using traditional Chinese medicine external treatment methods.

Ultra-high spectral purity laser derived from weak external distributed perturbation

Ultra-high spectral purity lasers are of considerable research interests in numerous fields such as coherent optical communication,microwave photonics,distributed optical fiber sensing,gravitational wave detection,optical clock,and so on.Herein,to deeply purify laser spectrum with compact size under normal condition,we propose a novel and practical idea to effectively suppress the spontaneous radiation of the laser cavity through weak external distributed perturbation.Subsequently,a laser configuration consisting of a main lasing cavity and an external distributed feedback cavity is proposed.The feedback signal with continuous spatio-temporal phase transition controlled by a distributed feedback structure is injected into the main cavity,which can deeply suppress the coupling rate from the spontaneous radiation to the stimulated emission and extremely purify the laser spectrum.Eventually,an ultra-narrow linewidth on-chip laser system with a side mode suppression ratio greater than 80 dB,an output linewidth of 10 Hz,and a relative intensity noise less than-150 dB/Hz is successfully obtained under normal conditions.The proposed concept in this work provides a new perspective for extreme regulation of laser parameters by using weak external distributed perturbation,which can be valid for various gain-type lasers with wide wavelength bands.

External blast flow field evolution and response mechanism of single-layer reticulated dome structure

Single-layer reticulated dome structure are commonly high-profile building in the public and can be attractive targets for terrorist bombings,so the public can benefit from enhanced safety with a stronger understanding of the behavior of single-layer reticulated dome structure under explosion.This paper investigates the fluid-structure interaction process and the dynamic response performance of the singlelayer reticulated dome under external blast load.Both experimental and numerical results shown that structural deformation is remarkably delayed compared with the velocity of blast wave,which advises the dynamic response of large-span reticulated dome structure has a negligible effect on the blast wave propagation under explosion.Four failure modes are identified by comparing the plastic development of each ring and the residual spatial geometric of the structure,i.e.,minor vibration,local depression,severe damage,and overall collapse.The plastic deformation energy and the displacement potential energy of the structure are the main consumers of the blast energy.In addition,the stress performance of the vertex member and the deep plastic ratio of the whole structure can serve as qualitative indicators to distinguish different failure modes.

An investigation of the influence of intestinal flora in external traditional Chinese medicine therapy

External therapy,which has been used for millennia to treat disease,has now become the newest member of complementary and alternative therapies.A growing number of clinical studies and animal experiments have shown that external therapy exerts a positive effect on the intestinal flora.In this paper,we review the research related to external therapy on various systemic diseases and focus on changes in the intestinal flora.We found that studies on external therapy are dominated by acupuncture and tuina,primarily aimed at the treatment of digestive and neurological diseases.However,the deeper mechanism of regulation of the intestinal flora by external therapy has not yet been experimentally confirmed.

Formation process of extension knee joint contracture following external immobilization in rats

BACKGROUND Current research lacks a model of knee extension contracture in rats.AIM To elucidate the formation process of knee extension contracture.METHODS We developed a rat model using an aluminum external fixator.Sixty male Sprague-Dawley rats with mature bones were divided into the control group(n=6)and groups that had the left knee immobilized with an aluminum external fixator for 1,2,and 3 d,and 1,2,3,4,6,and 8 wk(n=6 in each group).The passive extension range of motion,histology,and expression of fibrosis-related proteins were compared between the control group and the immobilization groups.RESULTS Myogenic contracture progressed very quickly during the initial 2 wk of immobilization.After 2 wk,the contracture gradually changed from myogenic to arthrogenic.The arthrogenic contracture progressed slowly during the 1^(st) week,rapidly progressed until the 3^(rd) week,and then showed a steady progression until the 4^(rd) week.Histological analyses confirmed that the anterior joint capsule of the extended fixed knee became increasingly thicker over time.Correspondingly,the level of transforming growth factor beta 1(TGF-β1)and phosphorylated mothers against decapentaplegic homolog 2(p-Smad2)in the anterior joint capsule also increased with the immobilization time.Over time,the cross-sectional area of muscle fibers gradually decreased,while the amount of intermuscular collagen and TGF-β1,p-Smad2,and p-Smad3 was increased.Unexpectedly,the amount of intermuscular collagen and TGF-β1,p-Smad2,and p-Smad3 was decreased during the late stage of immobilization(6-8 wk).The myogenic contracture was stabilized after 2 wk of immobilization,whereas the arthrogenic contracture was stabilized after 3 wk of immobilization and completely stable in 4 wk.CONCLUSION This rat model may be a useful tool to study the etiology of joint contracture and establish therapeutic approaches.

The mechanism of external pressure suppressing dendrites growth in Li metal batteries

Li metal is considered an ideal anode material for application in the next-generation secondary batteries.However,the commercial application of Li metal batteries has not yet been achieved due to the safety concern caused by Li dendrites growth.Despite the fact that many recent experimental studies found that external pressure suppresses the Li dendrites growth,the mechanism of the external pressure effect on Li dendrites remains poorly understood on the atomic scale.Herein,the large-scale molecular dynamics simulations of Li dendrites growth under different external pressure were performed with a machine learning potential,which has the quantum-mechanical accuracy.The simulation results reveal that the external pressure promotes the process of Li self-healing.With the increase of external pressure,the hole defects and Li dendrites would gradually fuse and disappear.This work provides a new perspective for understanding the mechanism for the impact of external pressure on Li dendrites.