制造发展的三个范式:制造发展规律的研究

基于对人类社会发展历史和科学技术发展内在规律的认识,本文详细分析了制造发展的三个范式,论证了原子及近原子尺度制造是制造范式III的核心使能技术。文章回顾了国内外各机构对原子级制造研发规划现状,指出我国目前处于原子级制造技术发展的重要战略机遇期,并从设计、材料、加工和检测等角度分析了原子级制造的技术体系内涵;梳理了原子级表面制造、原子级结构制造、原子级测量与表征等领域的研究进展,呈现了当前具有原子级制造能力的部分代表性技术,包括原子级切削、原子级抛光、电化学加工、等离子体原子级加工技术、原子精准操控以及原子分辨测量与表征技术,并对原子级制造战略规划提出发展建议。

Handheld bedside ultrasound in the diagnosis of myocarditis

Myocarditis is a disease process that every emergency physician fears missing.Its severity can be mild to life-threatening,and many cases are likely undetected because they are subclinical with nonspecifi c signs.[1]Subtle cardiac signs may be overshadowed by systemic symptoms of the underlying infectious process.Fever,myalgias,lethargy,symptoms commonly associated with viral syndrome,can mask the life-threatening myocarditis that may be present.In fact,in the United States Myocarditis Treatment Trial,almost 90%of patients reported symptoms consistent with a viral prodrome.[2]Ammirati et al[3]reported that 27%of patients with myocarditis had either reduced left ventricular ejection fraction,ventricular arrhythmias,or low cardiac output.Here,we present a case report,in which handheld point-of-care ultrasound was utilized at the bedside to aid in the critical diagnosis of myocarditis.With the additional information provided through this imaging modality,this patient was able to be transferred to the appropriate tertiary care facility in an expeditious manner and receive possible defi nitive treatment.

A case of phenibut withdrawal and treatment with baclofen

Phenibut(β-phenyl-γ-aminobutyric acid)is a psychoactive gamma-aminobutyric acid(GABA)analog marketed online as a nutritional and nootropic(cognition enhancing)supplement.Phenibut consumption poses a high risk of potential abuse.Withdrawal from phenibut mimics benzodiazepine and alcohol withdrawal and can be dangerous.A number of approaches have been described for phenibut withdrawal,including protocols that include baclofen,but for inpatient and outpatient use.Here we describe a 30-year-old male who presented to an emergency department(ED)with insomnia,anxiety and palpitations after he stopped taking phenibut.

Acute atraumatic pinna (auricular) perichondritis

Perichondritis of the external ear is referred to inthe literature as pinna perichondritis as well as auricularperichondritis. Pinna （auricular） perichondritis is aninfection involving cartilage and subcutaneous tissue.The resulting infection produces swelling which canbe severe, and can lead to focal ear necrosis. The termperichondritis may even be considered a misnomer＂as the cartilage is almost always involved.＂[1] Pinna（auricular） perichondritis presents with signs andsymptoms that can include pain。

An unusual case of renal calculi leading to myocardial infarction and cardiogenic shock

INTRODUCTION The presentation of cardiogenic shock(CS)is usually straightforward,and includes hypotension,absence of hypovolemia,and clinical signs of poor tissue perfusion such as oliguria,cyanosis,cool extremities and altered mentation.^([1])

An unusual emergency department case： ruptured ectopic pregnancy presenting as chest pain

INTRODUCTION Ectopic pregnancy occurs at a rate of 1%–2%of all pregnancies,and tends to occur at a higher rate(up to4%)in patients receiving fertility treatments.[1]Women with ectopic pregnancies are often asymptomatic or may complain of amenorrhea,vaginal spotting,and lower abdominal cramping pain.They may also report common symptoms of early pregnancy such as nausea,vomiting,

The Evolution of Reliability and Efficiency of Aerospace Bearing Systems

The worldwide air traffic underwent a rapid development in recent decades.?Between the early 70s and the late 90s of the last century civil air traffic?doubled every 15 years. The civil aviation market will continue to grow with 4% - 5%?each year within the next 20 years. This enormous growth represents major?challenges for airframers, engine makers, suppliers, airlines, air traffic management?and ground infrastructure. In addition, the public debate on the worldwide?civil air traffic is dominated by environmental and climate issues, even though only 2% of the man-made carbon dioxide (CO2) emissions are due to air transportation. Therefore the aerospace industry will have to focus on a low-emission and quite air traffic, and on the conservation of natural resources and our environment. The end-use consumer and environmental policy requirements?for aircrafts of the next generation translate into components with improved efficiency and reliability. Rolling bearings are one of these components which?significantly determine the reliability and mechanical efficiency of aerospace applications such as aircraft and rotorcraft engines and transmission systems.?They have to withstand very demanding operating conditions. Especially main shaft?bearings in modern aircraft engines experience high rotational speeds andtemperatures. Furthermore aerospace bearings have to meet the highest reliability?standards and require low-weight design solutions. These operating conditions?and requirements present a continuous challenge for improvements in all?fields of bearing technology. This article presents solutions in aspects of materials, design, analysis, and surface technologies in order to meet the environmental, reliability, and economical requirements of advanced aerospace bearing systems. State of the art bearing analysis and advanced bearing design solutions?contributing to lower friction power losses and increased systems efficiency?are discussed. Weight, functional, and maintenance benefits are presented with the example of highly integrated aircraft engine main shaft bearings. It is also shown that the progress in bearing materials and surface technology development is the basis for weight and friction energy reduction in aerospace?bearing systems.

关于伦敦圣三一钢琴考级的分析与思考

在诸多国际音乐考级系统中,伦敦圣三一音乐考级在19世纪的诞生对后来的国际音乐考级系统都产生了至关重要的影响。本文在针对伦敦圣三一钢琴考级的要求进行简要分析的同时,也对我国现行的钢琴教育进行了反思。

Hypoadiponectinemia: Association with risk of varying degrees of gestational hyperglycemia and with maternal ethnicity

Objective: The aims of this study were to examine the influence of maternal hypoadiponectinemia on the risk of varying degrees of gestational hyperglycemia as well as on ethnic differences in circulating levels of adiponectin. Methods: A case-control study nested within a prospective cohort of healthy pregnant women compared those who developed gestational diabetes mellitus (GDM, N = 80), or had an impaired glucose challenge test (GCT) non-GDM (defined as 1hr plasma glucose >140 mg/dl after a 50-g oral glucose load when screening for GDM but did not meet the diagnostic criteria for GDM by a diagnostic oral glucose tolerance test, N = 128) to normal controls (N = 557). Concentrations of serum adiponectin were determined at entry (~17 weeks) and during the 3rd trimester. Results: With multivariable adjustment, entry hypoadiponectinemia (the lowest tertile vs. other tertiles pooled) was strongly associated with an increased risk of GDM (AOR 2.68, 95% CI 1.62 - 4.41) and with impaired GCT non-GDM (AOR 1.58, 95% CI 1.05 - 2.38). This association persisted after adjustment for pregravid BMI despite the fact that the risk in obese women with low adiponectin was higher. Similar data were obtained during the 3rd trimester. The concentration of adiponectin during the 3rd trimester was significantly lower in African Americans compared to Hispanics or Caucasians and this difference was detectable in both cases and controls (p < 0.05 or p < 0.01 for each). Conclusions: The present results identified a unique graded association between hypoadiponectinemia during early pregnancy with risk of GDM and less severe hyperglycemia non-GDM independent of maternal BMI. The relationship persisted to the 3rd trimester. African American women have lower adiponectin level than Caucasian or Hispanic women. Hypoadiponectinemia may play a significant pathophysiological role in the development of GDM and of less severe gestational hyperglycemia.

Efficacy of morning-only 4 liter sulfa free polyethylene glycol vs 2 liter polyethylene glycol with ascorbic acid for afternoon colonoscopy

AIM:To compare the bowel cleansing efficacy of same day ingestion of 4-L sulfa-free polyethylene glycol(4-L SF-PEG)vs 2-L polyethylene glycol solution with ascorbic acid(2-L PEG+Asc)in patients undergoing afternoon colonoscopy.METHODS:206 patients(mean age 56.7 years,61%male)undergoing outpatient screening or surveillance colonoscopies were prospectively randomized to receive either 4-L SF-PEG(n=104)or 2-L PEG+Asc solution(n=102).Colonoscopies were performed by two blinded endoscopists.Bowel preparation was graded using the Ottawa scale.Each participant completed a satisfaction and side effect survey.RESULTS:There was no difference in patient demographics amongst groups.4-L SF-PEG resulted in better Ottawa scores compared to 2-L PEG+Asc,4.2 vs4.9(P=0.0186);left colon:1.33 vs 1.57 respectively(P=0.0224),right colon:1.38 vs 1.63 respectively(P=0.0097).No difference in Ottawa scores was found for the mid colon or amount of fluid.Patient satisfaction was similar for both arms but those assigned to 4-L SF-PEG reported less bloating:23.1%vs 11.5%(P=0.0235).Overall polyp detection,adenomatous polyp and advanced adenoma detection rates were similar between the two groups.CONCLUSION:Morning only 4-L SF-PEG provided superior cleansing with less bloating as compared to 2-L PEG+Asc bowel preparation for afternoon colonoscopy.Thus,future studies evaluating efficacy of morning only preparation for afternoon colonoscopy should use4-L SF-PEG as the standard comparator.

Model-Measurement Comparison of Ammonia Bi-Directional Air-Surface Exchange Fluxes over Agricultural Fields

Modeled and measured bi-directional fluxes (BDFs) of ammonia (NH3) were compared over fertilized soybean and corn canopies for three intensive sampling periods: the first, during the summer of 2002 in Warsaw, North Carolina (NC), USA;and the second and third during the summer of 2007 in Lillington, NC. For the first and the third experimental periods, the BDF model produced reasonable diurnal flux patterns. The model also produced correct flux directions (emission and dry deposition) and magnitudes under dry and wet canopy conditions and during day and nighttime for these two periods. However, the model fails to produce the observed very high upward fluxes from the second sampling period due to the fertilization application (and thus being much higher soil emission potentials in the field than the default model values), although this can be improved by adjusting model input of soil emission potentials. Model-measurement comparison results suggest that the model is likely capable for improving long-term or regional scale ammonia predictions if implemented in chemical transport models replace the traditional dry deposition models, although modifications are needed when applying to specific situations.

EGD Assisted Stapled Strictureplasty for Gastric Stricture after GIST Tumor Resection: A Case Report

A stricture formation resulting in impedance of gastric emptying is a fairly common complication after gastric surgery with endoscopy being the most direct way of diagnosis. When this and other methods fail in detecting the complication, the proper diagnosis can become challenging. We present an unusual case of an acquired gastric stricture after the gastrointestinal stromal tumor (GIST) resection. A stapled strictureplasty was completed with the simultaneous application of the diagnostic laparoscopy and the intra-operative EGD. We perform the comprehensive literature review (Pubmed-Cochrane 1990-current) diagnostic and surgical treatments of post resection gastric strictures.

A Lazarus effect： A case report of Bupropion overdose mimicking brain death

Dear editor,We report a case of a 47-year-old female who presented with a toxic bupropion ingestion leading to cardiac arrest.She initially exhibited a loss of brainstem reflexes in conjunction with burst-suppression pattern on EEG.Burst suppression is an EEG waveform pattern of alternating isoelectric suppressions and high voltage bursts.^([1])

Treating refractory depression in Parkinson’s disease:a meta-analysis of transcranial magnetic stimulation

Background:Parkinson’s disease(PD)is often accompanied by clinically identified depression.Providing effective pharmacotherapies that concomitantly treat both motor and psychological symptoms can pose a challenge to physicians.For this reason,alternatives to standard anti-depressant treatments,such as repetitive transcranial magnetic stimulation(rTMS),have been evaluated within the Parkinson’s population.Methods:A literature search was conducted on the PubMed database for all studies that evaluated rTMS as a treatment in patients with both depression and PD.A meta-analysis was performed on all studies that reported mean pre-and post-rTMS depression inventory scores.Widely used depression inventories included both self-report and clinician-administered measures.Effect size for individual study groups and across all studies was calculated.Results:Six of 7 studies meeting inclusion criteria reported significantly improved depression scores,large effect sizes,and significant p-values.Total weighted average effect size was calculated at 1.32 across all study groups that applied rTMS.Conclusions:Across all but one study,rTMS appears to effectively reduce depression scores among self-reported and clinician administered inventories.The total weight average effect size showed that,when considering study sample sizes and degree of findings,this form of neurostimulation can relieve PD patients of their depressive symptoms.Further,rTMS is a promising alternative to traditional anti-depressant therapies when treating refractory depression in patients with PD.

Anti-cancer mechanisms of action of therapeutic alternating electric fields(tumor treating fields[TTFields])

Despite improved survival outcomes across many cancer types,the prognosis remains grim for certain solid organ cancers including glioblastoma and pancreatic cancer.Invariably in these cancers,the control achieved by time-limited interventions such as traditional surgical resection,radiation therapy,and chemotherapy is short-lived.A new form of anti-cancer therapy called therapeutic alternating electric fields(AEFs)or tumor treating fields(TTFields)has been shown,either by itself or in combination with chemotherapy,to have anti-cancer effects that translate to improved survival outcomes in patients.Although the pre-clinical and clinical data are promising,the mechanisms of TTFields are not fully elucidated.Many investigations are underway to better understand how and why TTFields is able to selectively kill cancer cells and impede their proliferation.The purpose of this review is to summarize and discuss the reported mechanisms of action of TTFields from pre-clinical studies(both in vitro and in vivo).An improved understanding of how TTFields works will guide strategies focused on the timing and combination of TTFields with other therapies,to further improve survival outcomes in patients with solid organ cancers.

女性避孕：循证咨询

在有关女性避孕的综述中，Amy和Tripathi两位作者强调了患者选择的重要性，并且讨论了实际避孕失败率。但是，他们着重于激素类避孕药的使用，只稍稍分析了更为有效的避孕方式，比如子宫环。