Meta-silencer with designable timbre

Timbre,as one of the essential elements of sound,plays an important role in determining sound properties,whereas its manipulation has been remaining challenging for passive mechanical systems due to the intrinsic dispersion nature of resonances.Here,we present a meta-silencer supporting intensive mode density as well as highly tunable intrinsic loss and offering a fresh pathway for designable timbre in broadband.Strong global coupling is induced by intensive mode density and delicately modulated with the guidance of the theoretical model,which efficiently suppresses the resonance dispersion and provides desirable frequency-selective wave-manipulation capacity for timbre tuning.As proof-of-concept demonstrations for our design concepts,we propose three meta-silencers with the designing targets of high-efficiency broadband sound attenuation,efficiency-controlled sound attenuation and designable timbre,respectively.The proposed meta-silencers all operate in a broadband frequency range from 500 to 3200 Hz and feature deep-subwavelength sizes around 50 mm.Our work opens up a fundamental avenue to manipulate the timbre with passive resonances-controlled acoustic metamaterials and may inspire the development of novel multifunctional devices in noise-control engineering,impedance engineering,and architectural acoustics.

Acoustic Purcell effect induced by quasibound state in the continuum

We study theoretically and experimentally the acoustic Purcell effect induced by quasi-bound states in the continuum(quasiBICs).A theoretical framework describing the acoustic Purcell effect of a resonant system is developed based on the system’s radiative and dissipative factors,which reveals the critical emission condition for achieving optimum Purcell factors.We show that the quasiBICs contribute to highly confined acoustic field and bring about greatly enhanced acoustic emission,leading to strong Purcell effect.Our concept is demonstrated via two coupled resonators supporting a Friedrich-Wintgen quasiBIC,and the theoretical results are validated by the experiments observing emission enhancement of the sound source by nearly two orders of magnitude.Our work bridges the gap between the acoustic Purcell effect and acoustic BICs essential for enhanced wave-matter interaction and acoustic emission,which may contribute to the research of high-intensity sound sources,high-quality-factor acoustic devices and nonlinear acoustics.

Tunable Double-Band Perfect Absorbers via Acoustic Metasurfaces with Nesting Helical Tracks

We propose a design of tunable double-band perfect absorbers based on the resonance absorption in acoustic metasurfaces with nesting helical tracks and deep-subwavelength thicknesses(<λ/30 withλbeing the operation wavelength).By rotating the cover cap with an open aperture on the nesting helical tracks,we can tailor the effective lengths of resonant tubular cavities in the absorber at will,while the absorption peak frequency is flexibly shifted in spectrum and the acoustic impedance is roughly matched with air.The simulated particle velocity fields at different configurations reveal that sound absorption mainly occurs at the open aperture.Our experiment measurements agree well with the theoretical analysis and simulation,demonstrating the wide-spectrum and tunable absorption performance of the designed flat acoustic device.

Innovation Requirements and Progress of Dialysis Water Treatment System

With the development of medicine,people are becoming more and more aware of the quality of medical water supply,such as dial ysis water,dental water,preparation water,operating room water,supply room water.Therefore,People are constantly improving the water treatment system and its standardized,and the demand for dialysis water is also becoming more and more strict.Hemodialysis is an effective means of maintaining the life of renal failure patients,120~180L water will be used for a conventional dialysis treatment,and high flux dialysis will consume more.

Efficacy and Safety of Febuxost at in the Treatment of Chronic Kidney Disease with Hyperuricemia: A Meta- Analysis

Background Febuxostat and allopurinol have different pharmacological mechanisms,the efficacy of febuxostat in chronic kidney disease complicated with hyperuricemia remains controversial.A meta-analysis and systemic review was conducted to investigate the efficacy and safety of febuxostat in CKD populations complicated with hyperuricemia.Methods A comprehensive search was conducted in multiple electronic databases based on the inclusion and exclusion criteria,before December 2016,searching for the published studies,including Chinese and English,relating to the use of febuxostat in CKD populations complicated with hyperuricemia,and manual retrieval of the inclusion literature.Literature evaluation and data extraction were performed by two reviewers,Rev Man 5.3 was used to perform the meta-analysis.Results Seven studies with 482 CKD patients were included in the meta-analysis.We found that febuxostat can significantly slow the decreasing speed of e GFR[RR=4.90,95%CI(1.95,7.84),P=0.001],and reduce serum uric acid[RR=-99.30,95%CI(-172.24,-26.37),P=0.008]levels in CKD patients complicated with hyperuricemia when compairing with control group.There was no significant difference in the levels of systolic blood pressure[RR=-2.19,95%CI(-9.99,5.61),P=0.58],diastolic blood pressure[RR=-2.30,95%CI(-7.33,2.73),P=0.10],low density lipoprotein[RR=-0.47,95%CI(-7.64,6.69),P=0.90]between the two groups.Compared with the control group,the use of febuxostat increase the incidence of adverse reaction[RR=4.73,95%CI(1.04,21.43),P=0.04]in patients.Conclusions Febuxostat can significantly lower serum uric acid level and effectively delay the process of chronic renal failure in CKD patients complicated with hyperuricemic,increases the incidence of adverse reaction,no significant difference in SBP,DBP,LDL,when compared with control group.

Experimental Design and Clinical Observation of Modialysis Apparatus

Objective To evaluate the clinical safety and efficacy of polyethersulfone membrane hollow fiber dialyzer Enttex^(TM)-16LF(E60)in treating patients with end stage renal disease caused by a variety of reasons.Methods This clinical trialwas designed as a randomized,open,two-phase crossover and positive control,non-inferiority study.To evaluate the indicators of blood routine test,serum biochemical indexes,blood gas analysis,vital signsbefore and after hemodialysis,and the adverse events were recorded indetail.Results There was no significant difference in creatinine,urea,creatinine clearance and electrolytes between Enttex TM-16LF dialyzer and control dialyzer before and after hemodialysis,no adverse event associated with the Enttex^(TM)-16LF dialyzer was found during the study.Conclusions The Enttex^(TM)-16LF dialyzeris effective and safe for hemodialysis in patients with end stage renal disease.

The Research Progression of Calcitonin for the Therapy of Renal Osteodystrophy

Calcitonin is a common medicine used in the treatment of osteoporosis,which could restrain the activity of osteoclasts,stop the loss of osteocalcin and reduce the transfer of osteocalcin.Calcitonin can also be used in the treatment of the pain-caused diseases which usually cause by hypercalcemia and others such like Paget's disease and bone tumors.As is approved by several clinic researches,calcitonin is powerful in adjusting the level of calcium,phosphorus and PTH during the treatment of renal osteodystrophy.In addition,it could improves the life quality of the patients who suffered from chronic kidney disease(CKD)and extending their life period.At present,several studies have shown us Calcitonin could be treated in renal osteodystrophy.However,the treatment experiences of Calcitonin are still lacking.Better understanding of the clinical evaluation for calcitonin in the treatment of renal osteodystrophy will hopefully help us to improve outcomes for these patients.

The Pathogenesis of the Mechanism of FGF23 in Chronic Kidney Disease Patients with Vascular Calcification

Fibroblast growth factor 23(FGF23)is a protein synthesized by bone cell and the osteoblast with endocrine function.The main role of FGF23 is to regulate serum phosphorus and 1,25(OH)2 D3 levels,it also plays an important role in calcium and phosphorus metabolism.The role of FGF23 in renal disease is to inhibit of phosphorus reabsorption,promote urinary phosphorus excretion and maintain a stable blood phosphorus level.Patients with chronic kidney disease(CKD)have more risk to suffer cardiovascular disease(CVD)which is related to the abnormal metabolism of calcium and phosphorus.FGF23,as newly discovered cardiovascular risk marker,several studies have shown that FGF23 level associates with multiple cardiovascular risk factors in CKD patients,especially in CKD patients with vascular calcification.To explore its pathogenesis of vascular calcification in CKD patients is particularly important,and that may help to take appropriate measures to improve the prognosis of CKD patients.

Application Status and Prospect of Bio-artificial Liver

Liver failure which can be caused by viral hepatitis,alcohol,drugs,metabolic diseases,autoimmune processes or other fac tors is the end stage of chronic liver disease.Although liver transplantation is currently considered to be the primary treatment measures of chronic liver disease.Due to donor shortages,surgical complications and immune rejection,cell therapy has been extensively studied.?Hepa tocyte transplantation and artificial liver have evolved into a simpler alternative to liver failure treatment.Artificial liver can be used as Liver replacement therapy in patients who were waiting for the liver transplantation with chronic liver disease.The ideal biological artificial liver must have the liver material metabolism,detoxification,synthesis and secretion and other functions.Nowadays bio-artificial liver has carried out a large number of clinical trials and get some progress.?This article is now discuss the status of bio-artificial liver and its re placement therapy prospects.

Treatment of Sepsis by Hemofiltration Combined with Plasma Exchange in One Case

Female patients,44 years old,due to'regular peritoneal dialysis5 years,stomach ache 1 week'admission.Previous had 2 times for'Peritoneal dialysis related peritonitis'in hospital,after anti-infection treatment patients symptoms improved and discharged.1 week ago in patients admitted to hospital because of abdominal pain again.Physical:abdominal tenderness,bowel sounds hyperthyroidism.Laboratory inspection index:CRP:172.22 mg/l,WBC:23.26×10~9/L,NEU%:89.23%,D dimer:3 800 ng/ml,PCT:14.86 ng/ml。

基于微穿孔板和卷曲背腔复合结构的低频宽带吸声体

通过引入卷曲腔的概念并结合微穿孔板所设计的吸声结构具有深亚波长厚度、低频宽带吸声和高效吸声的特性.通过理论分析、数值模拟和实验,揭示了卷曲吸声结构工作的物理机制.首先在理论上分析单个吸声体的吸声性能并进行了数值和实验验证,两个吸声单体的共振频率分别为282和429 Hz.进一步,基于模耦合理论将低/高频吸声单体联合起来,设计出一个厚度只有100 mm(~λ/12,λ为相对低频吸声单体共振频率对应的波长),在较宽频带(232~533 Hz)内吸声系数大于0.5,在262~469 Hz内吸声系数大于0.8的宽频高效吸声结构.理论、仿真与实验结果符合较好.与传统的大体积吸声结构相比,本研究提出的轻薄高效吸声体具有结构简单和容易制造等特点,在低频噪声控制工程中有潜在的应用前景.

基于弱吸声单元耦合的轻薄宽频吸声结构

寻求具有深亚波长厚度的宽频强吸声体一直是声学研究及噪声控制工程领域中的难题.为拓宽吸声频带,传统设计思路将一系列强共振单元组成阵列,利用它们的吸声峰"拼接"成具有一定宽度的吸声频带.然而该设计要求每一个共振单元本身都具有非常高效的吸声性能,这种严苛的条件往往制约了整体结构的厚度.本文提出了一种新的设计理念,通过强化一系列弱共振单元之间的耦合作用来实现一种新型的轻薄宽频强吸声结构.基于该设计理念,尽管每个弱共振单元本身仅具有相当低的吸声峰值,但通过调控单元之间的耦合作用,使得整体吸声结构在宽频范围(870~3224 Hz)内实现吸声性能的大幅提升(平均吸声系数0.957),同时结构厚度相较于传统设计方法得到显著缩减(厚度仅3.9 cm).该研究为超薄宽频吸声结构研究开辟了新的途径,也为结构表面声阻抗调控相关研究领域提供了一种革新的设计思路.

Compact asymmetric sound absorber at the exceptional point

We present an asymmetric absorber at an exceptional point(EP) with a compact configuration and deep-subwavelength thickness.Unlike conventional side-branched sound absorbers in dual-port systems, the proposed asymmetric absorber exhibits a compact shape that is coaxial with the waveguide. By tuning the loss and geometric parameters of the non-Hermitian system to reach an EP, we observe extreme asymmetric absorption. This phenomenon is theoretically and experimentally validated by observing a quasi-perfect absorption and a near-total reflection for opposite incidences at the ultra-thin(1/28 th of the operating wavelength)neck-embedded tube employed in this study. Furthermore, we demonstrate an EP-induced tunable asymmetric absorption. Our study proposes novel approaches to manipulate the EP-induced wave phenomena, paving the way for the development of novel acoustic absorbers, sensors, isolators, and directional devices.