Reliability Analysis of Some Queueing Models with Reparable Service Station

In this paper, we give a reliability anlysis of some queueing modesl with reparable service station. By using the method of supplementary variable,we obtained some system characters and reliability indices of the service station.

Catania flatfoot score:A diagnostic-therapeutic evaluation tool in children

BACKGROUND Flexible flatfoot(FFF)is a very common condition in children,but no evidencebased guidelines or assessment tools exist.Yet,surgical indication is left to the surgeon’s experience and preferences.AIM To develop a functional clinical score for FFF[Catania flatfoot(CTF)score]and a measure of internal consistency;to evaluate inter-observer and intra-observer reliability of the CTF Score;to provide a strong tool for proper FFF surgical indication.METHODS CTF is a medically compiled score of four main domains for a total of twelve items:Patient features,Pain,Clinical Parameters,and Functionality.Each item refers to a specific rate.Five experienced observers answered 10 case reports according to the CTF.To assess inter-and intra-observer reliability of the CTF score,the intra-class correlation coefficients’(ICCs)statistics test was performed,as well as to gauge the correlation between the CTF score and the surgical or conservative treatment indication.Values of 75%were chosen as the score cut-off for surgical indication.Sensitivity,specificity,positive likelihood ratio(PLHR),negative likelihood ratio(NLHR),positive predictive value(PPV),and negative predictive value(NPV).RESULTS Overall interobserver reliability ICC was 0.87[95%confidence interval(CI):0.846-0.892;P<0.001].Overall intra-observer reliability ICC was 0.883(95%CI:0.854-0.909;P<0.001).A direct correlation between the CTF score and surgical treatment indication[Pearson correlation coefficient=0.94(P<0.001)]was found.According to the 75%cut-off,the sensitivity was 100%(95%CI:83.43%-100%),specificity was 85.71%(95%CI:75.29%-92.93%),PLHR was 7(95%CI:3.94-12.43),NLHR was 0(95%CI:0-0),PPV was 75%(95%CI:62.83%-84.19%)and NPV was 100%(95%CI:100%-100%).CONCLUSION CTF represents a useful tool for orthopedic surgeons in the FFF evaluation.The CTF score is a quality questionnaire to reproduce suitable clinical research,survey studies,and clinical practice.Moreover,the 75%cutoff is an important threshold for surgical indication and helps in the decision-making process.

Medium and long-term thermal coal contract embedded reparations from the perspective of an evolutionary game

Coal-fired electricity enterprises are caught in the dilemma of relative fixed prices and rising costs under the scenario of decarbonization.Meanwhile,soaring market-oriented coal pricing results in coal enterprises’increasing defaults on thermal coal medium-and long-term contracts(MLC).To investigate the implementation of MLC at the micro-level,this study formalized the contractual behaviors of coal and coal-fired electricity enterprises based on the asymmetric evolutionary game.We formalized the evolving behaviors of both parties using replicator dynamics equations and proved that there were two evolutionary stabilization strategies(ESSs):compliance and coal enterprises’unilateral default.A multi-agent-based simulation was applied to verify the evolving process of ESSs and determine the critical values of MLC design by sensitive analysis.From the simulation results,coal-fired electricity enterprises do not stop generation under the current carbon quota allocation mechanism,even if carbon emission trading increases electricity generation costs.Coal enterprises choose to“default”when the market price of coal is higher than the contracted price by 18%.However,if the original reparation is increased by 5%,the compliance rate of the coal enterprises improves.Dynamic reparations embedded in the MLC improved enforcement during the contracting period.Moreover,the proposed policy implications have practical significance for enhancing the coordinated operation of coal-electricity energy supply chains.

The Effects of Tissue Regenerative Status on Hormesis in Dogs Irradiated during Their Lifespan

The goal of this study was to evaluate the influence of natural variation in the regenerative status of dog tissues on the signs of hormesis, which are evident after total body exposure to low daily doses of external gamma radiation throughout the lifespan. Ninety beagle dogs of both sexes were irradiated with cobalt 60 at 0.003 Gy/day commencing 1 year after birth to death. Control (n = 169) and irradiated animals underwent whole-life clinical observation and autopsy, and were then retrospectively divided into two subgroups with (W) or without benign tumors or tumors of unknown nature (WO) that were clinically recorded on single days throughout the lifespan. Radiation hormesis was only detected in subgroup WO, which had life span (LS) of 10.7 years in the absence of radiation. The radiogenic prolongation of life to 11.8 years in the WO subgroup (p 【0.05) was similar to that in the W control and irradiated W subgroups (11.8 and 11.5 years, respectively). The number of solid malignancies found upon autopsy of the control WO subgroup was less (39.5%) than that evident in the control W subgroup (60%). Compared to the irradiated W subgroup, irradiation of the WO subgroup was accompanied by a slight increase (1.14-fold) in the number of solid malignancies evident at autopsy and in the clinical signs of tissue atrophy and body weight loss (2.4-fold and 2.4-fold, respectively), but was accompanied by strong reductions in the extent of anemia and hemoblastoses (】10-fold for both). The data exclude the notion that radiation is associated with healing, but suggest that certain pathologies (e.g., hemoblastoses) may be substituted with other less dangerous somatic diseases in weaker animals only.

Accuracy of the rotator cuff reparability score

BACKGROUND The reparability of large or massive rotator cuff tears is difficult to determine preoperatively.We previously identified age≥65 years,acromiohumeral interval≤6 mm,and anteroposterior tear size≥22 mm as risk factors for rotator cuff repair failure.We therefore developed a rotator cuff reparability score where each of the above risk factors is assigned a score of one point.AIM To determine the accuracy of a rotator cuff reparability score.METHODS This was a retrospective cohort study of recruited patients with large or massive rotator cuff tears treated at our institution between January 2013 and December 2019.Exclusion criteria were revision surgery and patients with contraindications for surgery.All patients underwent arthroscopic rotator cuff repair and were categorized into either complete or partial rotator cuff repair.Rotator cuff reparability scores were calculated for each patient.The sensitivity,specificity,positive and negative predictive value,and positive and negative likelihood ratio were assessed.A receiver operating characteristic curve was plotted to determine the optimal cut-off rotator cuff reparability score.RESULTS Eighty patients(mean age,61 years;range,25–84 years;41 females and 39 males)were recruited.Intra-and inter-observer reliabilities were good to excellent.The number of patients with 0,1,2,and 3 risk factors for rotator cuff repair failure were 24,33,17,and 6,respectively.Complete repair was performed in all patients without risk factors.Two of the 33 patients with one risk factor and seven of the 17 patients with two risk factors underwent partial repair.One of the six patients with three risk factors underwent complete repair.The area under the curve was 0.894.The optimal cut-off score was two points with a sensitivity of 85.71%and a specificity of 83.33%.CONCLUSION A rotator cuff reparability score of two was determined to be the optimal cut-off score for predicting the reparability of large or massive rotator cuff tears.

Visiting Patients at Home: Reasons and Efficiency of Dental House Calls

This retrospective study analyzes indications for house calls by dentists in a domiciliary setting. Its database consists in 69 visits made by a dentist office in Munich from 1998 to 2013 at the homes of 29 non-institutionalized seniors (≥62 years old, 15 females, 14 males, average age 83.7 years old). The analysis focused on the patients’ general state of health, their dental and oral health, the kinds of dental treatments administered, as well as economic aspects and the quantitative development in the frequency of house calls during the study period. The most frequent pre-existing conditions that made a house call necessary were cardiovascular illnesses (60%) and dementia diseases (36%). Multi-morbidity, dependency on care, accessibility issues, and frailty because of advanced age played a central role. The patients’ oral health was acceptable, with the exception of those with dementia diseases, who were more frequently toothless (40% versus 5.6%) and had a higher percentage of carious and decayed teeth (26.3% versus 10.3%). The most frequent procedures were treatments for denture sores and the repair of removable dentures (53.6%). The main focus was on reparative dentistry. The average house call took 37 minutes including travel time. Thus, the time needed was a multiple of the time necessary for treatment in the dental office. The lack of economic efficiency may be the reason why many dentists in Germany hesitate to make house calls. Despite the introduction of additional fees for the treatment of patients in need of long-term care on April 1, 2013, the number of house calls is low and increases only slowly. At the same time, the need for house calls will rise in the future due to an increasing proportion of elderly persons in the population and a decline in the percentage of toothless elderly.

Pathogenesis of Cancer: Cancer Reparative Trap

Cancer is one of the leading causes of death in the world while the long-term prognosis is still unfavorable, despite the enormous efforts in the search for effective anti-cancer drugs. We think that the obstacle for creating of effective anti-cancer drugs could be existing idea that the basis of cancer is caused by the damage of the genetic apparatus of the cell. In this paper, we present the pathogenesis of cancer which is based on the formation of the special sustainable pathophysiological state of the organism what we call the state of “cancer reparative trap”. The essence of this pathophysiological state of the organism is in the reparative orientation of the immune system of cancer patients, when constant tissue repair is accompanied by systemic suppression of the anti-tumor immunity. Specifically, during the long-term exposure to carcinogens (exogenous and/or endogenous), the continuous tissue damage occurs which induces permanent stimulation of cell proliferation (imbalanced Th1 < Th2 lymphocytes, M1 < M2 macrophages, inflammation, angiogenesis, etc.) in order to repair the tissues damaged. At the same time, tissue repair is necessarily accompanied by the suppression of anti-tumor immunity (increase in T-regulatory cells, imbalanced Th1 Th2 lymphocytes, M1 < M2 macrophages et al.), which creates the necessary conditions for the survival of the malignantly transformed cells, formed by the action of carcinogens. The determining role of the imbalance in the autonomous nervous system (simpathetic/hypersympathetic dominance) in the development, maintenance and generalization of the cancer process has been shown. The explanation of a number of phenomena has been presented: the cell resistance to chemotherapy, and the phenomenon of cancer cell dormancy. The promising approaches for the cancer management in clinical practice have been proposed.

The State of White Supremacy in America:It Is Time to Stand Together

The United States has numerous social-cultural issues affecting its population.One of these problems is white supremacy.This concept refers to a racist perception that white persons are naturally superior to individuals of other races and should thus dominate them.While white supremacy in previous centuries galvanized a lot of support among white people,the concept is now regarded vicious by white,African American,Latino as well as other races.The modern American society is structured under cultural sensitiveness,racial equality,and religious tolerance.Unlike the years of slavery or reconstruction,all citizens in the United States are afforded equal rights irrespective of their cultural identities.Nevertheless,white supremacist notions persist in a nation that prides itself for its democratic model,cultural diversity,religious tolerance and socioeconomic transcendence.The state of white supremacy is that America can be manifested by violence,imperialistic tendencies,discrimination in the society,unfair immigration policies,poor political leadership,and the deplorable role of the media.With the growing number of atrocities being committed around the United States by both members of identified and non-identified white supremacist group,it is time to address this issue together.This paper,is a constructive discussion venting the many ills of racial discrimination in every aspect that affects minorities at all spheres of the society and the deplorable state of white supremacy in America.

A Rare Case of Reparative Granuloma of Nasal Cavity

Giant cell reparative granuloma (GCRG) is a rare, benign tumour that mostly involves the maxilla and mandible. It is rare in the nasal cavity and paranasal sinuses. Here we report a case of GCRG of nasal cavity in 24-year-old man who came with unilateral nasal obstruction, epistaxis and proptosis. CT scan showed soft tissue hypodensity lesion of left nasal cavity. Endoscopic surgical excision and biopsy were done. The pathology was consistent with GCRG. There was no recurrence seen on follow-up for 2 years. A short literature review about diagnosis, clinical behavior, radiological findings and treatment of this tumor entity are given.

Racial Disparities in the United States Criminal Justice System:“With Liberty and Justice for All?”

Racial discrimination remains a prevalent issue in the contemporary U.S.despite efforts to promote equality.Many young African American and Hispanic males are easy target for law enforcement agents.Minorities experience a higher and more unfair form of racial discrimination,racial profiling,police brutality,unfair sentencing,and mass incarceration for offences which are the same or less than those committed by White males.The rate of incarceration in the United States is five to eight times higher than most developed countries,and Black males constitute the largest percentage of inmates in the U.S.prison system.Once arrested,Black Americans are more likely to remain in prison longer,and await trial for minor offenses at a higher rate than Whites.Black and Latino males sentenced in state and federal courts face significantly greater odds of incarceration than White offenders for the same or even higher crimes.Vagins and McCurdy in a 2006 ACLU on“cracks in the system”reported that“There is no rational medical or penological reason for the 100:1 disparity between crack and powder cocaine and instead it causes an unjustified racial disparity in our penal system”(p.7).There is a racial disparity in the proportion of Black males in prison serving sentences of life without the possibility of parole(LWOP).In addition,The United States Criminal Justice System needs to be carefully examined as a top priority agenda needing immediate call of action that needs reform to guarantee the constitutional rights accorded to every American“with liberty and justice for all”.

Degradation behavior of ZE21C magnesium alloy suture anchors and their effect on ligament-bone junction repair

Current materials comprising suture anchors used to reconstruct ligament-bone junctions still have limitation in biocompatibility,degradability or mechanical properties.Magnesium alloys are potential bone implant materials,and Mg^(2+) has been shown to promote ligament-bone healing.Here,we used Mg-2 wt.%Zn-0.5 wt.%Y-1 wt.%Nd-0.5 wt.%Zr(ZE21C)alloy and Ti6Al4V(TC4)alloy to prepare suture anchors to reconstruct the patellar ligament-tibia in SD rats.We studied the degradation behavior of the ZE21C suture anchor via in vitro and in vivo experiments and assessed its reparative effect on the ligament-bone junction.In vitro,the ZE21C suture anchor degraded gradually,and calcium and phosphorus products accumulated on its surface during degradation.In vivo,the ZE21C suture anchor could maintain its mechanical integrity within 12 weeks of implantation in rats.The tail of the ZE21C suture anchor in high stress concentration degraded rapidly during the early implantation stage(0-4weeks),while bone healing accelerated the degradation of the anchor head in the late implantation stage(4-12weeks).Radiological,histological,and biomechanical assays indicated that the ZE21C suture anchor promoted bone healing above the suture anchor and fibrocartilaginous interface regeneration in the ligament-bone junction,leading to better biomechanical strength than the TC4 group.Hence,this study provides a basis for further research on the clinical application of degradable magnesium alloy suture anchors.

GopPAR:一个新的饭店绩效评价指标

设计完善的绩效评价指标体系是保证饭店快速发展的前提 ,而要做到这一点 ,首要的任务在于选择适合本国国情的绩效评价指标。本文根据国内外饭店业绩效评价的现状 ,并结合我国饭店业的特点 ,介绍和引入了一个新的、适合我国实际的饭店财务绩效评价指标———GopPAR。

High-Quality Single-Layer Graphene via Reparative Reduction of Graphene Oxide

Reduction of graphene oxide （GO） is a promising low-cost synthetic approach to bulk graphene, which offers an accessible route to transparent conducting films and flexible electronics. Unfortunately, the release of oxygen-containing functional groups inevitably leaves behind vacancies and topological defects on the reduced GO sheet, and its low electrical conductivity hinders the development of practical applications. Here, we present a strategy for real-time repair of the newborn vacancies with carbon radicals produced by thermal decomposition of a suitable precursor. The sheet conductivity of thus-obtained single-layer graphene was raised more than six-fold to 350-410 S/cm （whilst retaining 〉96% transparency）. X-ray photoelectron spectroscopy （XPS） and Raman spectroscopy revealed that the conductivity enhancement can be attributed to the formation of additional sp2-C structures. This method provides a simple and efficient process for obtaining highly conductive transparent graphene films.

Vascular restoration therapy and bioresorbable vascular scaffold

This article describes the evolution of minimally invasive intervention technologies for vascular restoration therapy from early-stage balloon angioplasty in 1970s,metallic bare metal stent and metallic drug-eluting stent technologies in 1990s and 2000s,to bioresorbable vascular scaffold(BVS)technology in large-scale development in recent years.The history,the current stage,the challenges and the future of BVS development are discussed in detail as the best available approach for vascular restoration therapy.The criteria of materials selection,design and processing principles of BVS,and the corresponding clinical trial results are also summarized in this article.

Tailoring the Properties of Diels-Alder Reaction Crosslinked High-performance Thermosets by Different Bismaleimides

A series of Diels-Alder reaction cross-linked thermosets with recyclability and healability were prepared from furan-containing aromatic polyamide and bismaleimides with different chemical structures.The structures of synthesized bismaleimides were confirmed by 1 H nuclear magnetic resonance(1 H-NMR)spectroscopy;their reversible cross-linking with the furanic polyamide was further detected by 1 H-NMR technique and sol-gel transition behavior.The dynamic mechanical analysis and tensile test revealed the variable thermal and mechanical properties of thermosets cross-linked by different bismaleimides and with different molar ratios of maleimide group to furan group(Ima/fur).The tensile test also demonstrated that the better recyclability and solvent-assisted healability of thermosets cross-linked could be achieved by more flexible bismaleimides.This work is expected to provide valuable information for design of recyclable and healable high-performance thermosets with desired properties.

Fault self-repair strategy based on evolvable hardware and reparation balance technology

In the face of harsh natural environment applications such as earth-orbiting and deep space satellites, underwater sea vehicles, strong electromagnetic interference and temperature stress,the circuits faults appear easily. Circuit faults will inevitably lead to serious losses of availability or impeded mission success without self-repair over the mission duration. Traditional fault-repair methods based on redundant fault-tolerant technique are straightforward to implement, yet their area, power and weight cost can be excessive. Moreover they utilize all plug-in or component level circuits to realize redundant backup, such that their applicability is limited. Hence, a novel selfrepair technology based on evolvable hardware（EHW） and reparation balance technology（RBT） is proposed. Its cost is low, and fault self-repair of various circuits and devices can be realized through dynamic configuration. Making full use of the fault signals, correcting circuit can be found through EHW technique to realize the balance and compensation of the fault output-signals. In this paper, the self-repair model was analyzed which based on EHW and RBT technique, the specific self-repair strategy was studied, the corresponding self-repair circuit fault system was designed, and the typical faults were simulated and analyzed which combined with the actual electronic devices. Simulation results demonstrated that the proposed fault self-repair strategy was feasible. Compared to traditional techniques, fault self-repair based on EHW consumes fewer hardware resources, and the scope of fault self-repair was expanded significantly.

Optimal design of RTCs in digital circuit fault self-repair based on global signal optimization

Since digital circuits have been widely and thoroughly applied in various fields, electronic systems are increasingly more complicated and require greater reliability. Faults may occur in electronic systems in complicated environments. If immediate field repairs are not made on the faults, electronic systems will not run normally, and this will lead to serious losses. The traditional method for improving system reliability based on redundant fault-tolerant technique has been unable to meet the requirements. Therefore, on the basis of(evolvable hardware)-based and(reparation balance technology)-based electronic circuit fault self-repair strategy proposed in our preliminary work, the optimal design of rectification circuits(RTCs) in electronic circuit fault self-repair based on global signal optimization is deeply researched in this paper. First of all, the basic theory of RTC optimal design based on global signal optimization is proposed. Secondly, relevant considerations and suitable ranges are analyzed. Then, the basic flow of RTC optimal design is researched. Eventually, a typical circuit is selected for simulation verification, and detailed simulated analysis is made on five circumstances that occur during RTC evolution. The simulation results prove that compared with the conventional design method based RTC, the global signal optimization design method based RTC is lower in hardware cost, faster in circuit evolution, higher in convergent precision, and higher in circuit evolution success rate. Therefore, the global signal optimization based RTC optimal design method applied in the electronic circuit fault self-repair technology is proven to be feasible, effective, and advantageous.