THE EFFECT OF TENNIS RACKET STRING VIBRATION ABSORBER PLACEMENT ON TENNIS RACKET VIBRATIONS

The purpose of this research was to analyze the vibration effect of tennis racket caused by impact on different locative vibration absorber and locations. In this experiment, The tennis racket was fixed and kept the face horizontalized to the ground with 50 Ib on strings. A tennis ball was dropped from one meter height to impact three locations of the racket. The different locative vibration absorber was fixed on the racket. It was installed an accelerometer to capture the vibration signal of the handle of the racket. After the experiment, the data was used logarithmic decrement to calculate damping ratio. It was illustrated when the vibration absorber in Back and Tip to have obvious effect. But in Side, it could not effectively decrease the vibration compared with the racket without absorber

Delayed Uterine Rupture After Fetal Reduction in a Case of Cornual Heterotopic Pregnancy

SummaryObjectiveAssisted reproductive technology has contributed to the rising rate of multiple and ectopic pregnancies. We report a case of heterotopic cornual pregnancy with delayed uterine rupture despite successful fetal reduction. To our knowledge, this has not been previously reported.Case ReportA 32-year-old woman, gravida 2, para 0, had secondary infertility. She had undergone laparoscopic tuboplasty for bilateral tubal obstruction and laparoscopic bilateral salpingectomy for hydrosalpinx. Successful pregnancy was achieved after transfer of five frozen embryos for this pregnancy. At 7 weeks of gestation, routine pelvic sonography identified three gestational sacs, two in the intrauterine cavity and one in the right cornua. Fetal reduction with potassium chloride injection into the cornual pregnancy was performed at 8 weeks of gestation in a private clinic. At 13 weeks of gestation, she had sudden-onset low abdominal pain and hypovolemic shock. Emergency laparotomy revealed right cornual rupture, with a 3.4-cm translucent sac extruding into the peritoneal cavity. The uterus was repaired by simple closure of the right cornua. The twins survived the operation and were born smoothly at 34 weeks of gestation by cesarean section due to preterm labor and malpresentation.ConclusionUterine rupture can occur in women who have undergone successful fetal reduction for cornual heterotopic pregnancy

Cross Tropopause Transport of Water by Mid-Latitude Deep Convective Storms: A Review

Recent observational and numerical modeling studies of the mechanisms which transport moisture to the stratosphere by deep convective storms at mid-latitudes are reviewed. Observational evidence of the cross-tropopause transport of moisture by thunderstorms includes satellite, aircraft and ground-based data. The primary satellite evidence is taken from both conventional satellite of thunderstorm images and CloudSat vertical cloud cross-section images. The conventional satellite images show cirrus plumes above the anvil tops of some of the convective storms where the anvils are already at the tropopause level. The CloudSat image shows an indication of penetration of cirrus plume into the stratosphere. The aircraft observations consist of earlier observations of the ¡§jumping cirrus¡¨ phenomenon reported by Fujita and recent detection of ice particles in the stratospheric air associated with deep convective storms. The ground-based observations are video camera records of the jumping cirrus phenomenon occurring at the top of thunderstorm cells. Numerical model studies of the penetrative deep convective storms were performed utilizing a three-dimensional cloud dynamical model to simulate a typical severe storm which occurred in the US Midwest region on 2 August 1981. Model results indicate two physical mechanisms that cause water to be injected into the stratosphere from the storm: (1) the jumping cirrus mechanism which is caused by the gravity wave breaking at the cloud top, and (2) an instability caused by turbulent mixing in the outer shell of the overshooting dome. Implications of the penetrative convection on global processes and a brief future outlook are discussed

Automated Classification Model With OTSU and CNN Method for Premature Ventricular Contraction Detection

Premature ventricular contraction (PVC) is one of the most common arrhythmias which can cause palpitation, cardiac arrest, and other symptoms affecting the work and rest activities of a patient. However, patients hardly decipher their own feelings to determine the severity of the disease thus, requiring a professional medical diagnosis. This study proposes a novel method based on image processing and convolutional neural network (CNN) to extract electrocardiography (ECG) curves from scanned ECG images derived from clinical ECG reports, and segment and classify heartbeats in the absence of a digital ECG data. The ECG curve is extracted using a comprehensive algorithm that combines the OTSU algorithm with erosion and dilation. This algorithm can efficiently and accurately separate the ECG curve from the ECG background grid. The performance of the classification model was evaluated and optimized using hundreds of clinical ECG data collected from Fujian Provincial Hospital. Additionally, thousands of clinical ECG reports were scanned to digital images as the test set to confirm the accuracy of the algorithm for practical application. Results showed that the average sensitivity, specificity, positive predictive value, and accuracy of the proposed model on the MIT-BIH dataset were 95.47%, 97.72%, 98.75%, and 98.25%, respectively. The classification average sensitivity, specificity, positive predictive value, and accuracy based on clinical scanned ECG images can reach to 97.24%, 81.6%, 83.8%, and 89.33%, respectively, and the clinical feasibility is high. Overall, the proposed method can extract ECG curves from scanned ECG images efficiently and accurately. Furthermore, it performs well on heartbeat classification of normal (N) and ventricular premature heartbeat

Do beta-adrenergic blocking agents increase asthma exacerbation? A network meta-analysis of randomized controlled trials

Beta-adrenergic blocking agents (abbreviated as beta-blockers) have been used for treating various cardiovascular diseases. However, the potential for asthma exacerbation is one of the major adverse effects of beta-blockers. This study aimed to compare the level of risk for an asthma attack in patients receiving various beta-blockers. We searched for randomized controlled trials (RCTs) of either placebo-controlled or active-controlled design. The current network meta-analysis (NMA) was conducted under a frequentist model. The primary outcome was the incidence of asthmatic attack. A total of 24 RCTs were included. Overall NMA revealed that only oral timolol [risk ratio (RR) = 3.35 (95% confidence interval (CI) 1.04–10.85)] and infusion of propranolol [RR = 10.19 (95% CI 1.29–80.41)] were associated with significantly higher incidences of asthma attack than the placebo, whereas oral celiprolol [RR = 0.39 (95% CI 0.04–4.11)], oral celiprolol and propranolol [RR = 0.46 (95% CI 0.02–11.65)], oral bisoprolol [RR = 0.46 (95% CI 0.02–11.65)], oral atenolol [RR = 0.51 (95% CI 0.20–1.28)], infusion of practolol [RR = 0.80 (95% CI 0.03–25.14)], and infusion of sotalol [RR = 0.91 (95% CI 0.08–10.65)] were associated with relatively lower incidences of asthma attack than the placebo. In participants with a baseline asthma history, in addition to oral timolol and infusion of propranolol, oral labetalol, oxprenolol, propranolol, and metoprolol exhibited significantly higher incidences of asthma attack than did the placebo. In conclusion, oral timolol and infusion of propranolol were associated with a significantly higher risk of developing an asthma attack in patients, especially in those with a baseline asthma history, and should be avoided in patients who present a risk of asthma

Novel Nanohybrids of Silver Particles on Clay Platelets for Inhibiting Silver-Resistant Bacteria

We develop a novel nanohybrid showing a strong antibacterial activity on all of the tested pathogens, including methicillin-resistant Staphylococcus auerus and silver-resistant E. coli. The nanohybrid consists of silver nanoparticles (AgNPs) supported on 1 nm-thick silicate platelets (NSPs). The AgNP/NSP nanohybrid enables to encapsulate bacteria and triggers death signals from the cell membrane. The geographic shape of the NSPs concentrates AgNPs but impedes their penetration into attached cells, mitigating the detrimental effect of silver ion deposition in applied tissues. Moreover, the tightly tethered AgNPs on NSP surface achieve a stronger biocidal effect than silver nitrate, but bypassing Ag+ mechanism, on silver-resistant bacteria. This nanohybrid presents an effective and safe antimicrobial agent in a new perspective

Quantum liquid-crystal order in resonant atomic gases

I review recent studies that predict quantum liquid-crystalline orders in resonant atomic gases. As examples of such putative systems I will discuss an s-wave resonant imbalanced Fermi gas and a p-wave resonant Bose gas. In the former, the liquid-crystalline smectic, nematic and rich variety of other descendant states emerge from strongly quantum- and thermally- fluctuating Fulde-Ferrell and Larkin-Ovchinnikov states, driven by a competition between resonant pairing and Fermi-surface mismatch. In the latter, at intermediate detuning the p-wave resonant interaction generically drives Bose-condensation at a finite momentum, set by a competition between atomic kinetic energy and atom-molecule hybridization. Because of the underlying rotationally-invariant environment of the atomic gas trapped isotropically, the putative striped superfluid is a realization of a quantum superfluid smectic, that can melt into a variety of interesting phases, such as a quantum nematic. I will discuss the corresponding rich phase diagrams and transitions, as well the low-energy properties of the phases and fractional topological defects generic to striped superfluids and their fluctuation-driven descendants.Comment: Invited Review, 25 pages, 17 figure

Identification of Enriched Driver Gene Alterations in Subgroups of Non-Small Cell Lung Cancer Patients Based on Histology and Smoking Status

BACKGROUND: Appropriate patient selection is needed for targeted therapies that are efficacious only in patients with specific genetic alterations. We aimed to define subgroups of patients with candidate driver genes in patients with non-small cell lung cancer. METHODS: Patients with primary lung cancer who underwent clinical genetic tests at Guangdong General Hospital were enrolled. Driver genes were detected by sequencing, high-resolution melt analysis, qPCR, or multiple PCR and RACE methods. RESULTS: 524 patients were enrolled in this study, and the differences in driver gene alterations among subgroups were analyzed based on histology and smoking status. In a subgroup of non-smokers with adenocarcinoma, EGFR was the most frequently altered gene, with a mutation rate of 49.8%, followed by EML4-ALK (9.3%), PTEN (9.1%), PIK3CA (5.2%), c-Met (4.8%), KRAS (4.5%), STK11 (2.7%), and BRAF (1.9%). The three most frequently altered genes in a subgroup of smokers with adenocarcinoma were EGFR (22.0%), STK11 (19.0%), and KRAS (12.0%). We only found EGFR (8.0%), c-Met (2.8%), and PIK3CA (2.6%) alterations in the non-smoker with squamous cell carcinoma (SCC) subgroup. PTEN (16.1%), STK11 (8.3%), and PIK3CA (7.2%) were the three most frequently enriched genes in smokers with SCC. DDR2 and FGFR2 only presented in smokers with SCC (4.4% and 2.2%, respectively). Among these four subgroups, the differences in EGFR, KRAS, and PTEN mutations were statistically significant. CONCLUSION: The distinct features of driver gene alterations in different subgroups based on histology and smoking status were helpful in defining patients for future clinical trials that target these genes. This study also suggests that we may consider patients with infrequent alterations of driver genes as having rare or orphan diseases that should be managed with special molecularly targeted therapies

Efficacy of pharmacologic treatment in tinnitus patients without specific or treatable origin: A network meta-analysis of randomised controlled trials

Background- Although tinnitus has a prevalence between 20 and 42.8%, the currently recommended management for tinnitus, such as tinnitus support and psychologic therapies, are relatively time-consuming and expensive. Several new pharmacologic treatments designed for tinnitus patients without specific origin had been developed but their efficacy remains unclear. Methods- The current Network Meta-Analysis (NMA) of randomised controlled trials (RCTs) was conducted to evaluate the efficacy of different pharmacologic treatments for tinnitus management in tinnitus patients without specific or treatable origin (i.e. primary tinnitus). Databases were searched from inception to April 5th, 2021. All network meta-analytic procedures were conducted under the frequentist model. We calculated the effect size of outcomes with different rating scales with standardized mean difference. PROSPERO registration: CRD42020177742. Findings- Overall, 36 RCTs were included with 2,761 participants. The main results revealed that pharmacologic interventions with brain-acting effect (for example, amitriptyline, acamprosate, and gabapentin) and those with anti-inflammation/anti-oxidant effect (for example, intra-tympanic dexamethasone injection plus oral melatonin) were associated with superior improvement in tinnitus severity and response rate compared to placebo/control. Oral amitriptyline were associated with the highest improvement in tinnitus severity and the fourth highest response rate. None of the investigated interventions was associated with different changes in quality of life compared to placebo/control. All the investigated treatments were associated with similar drop-out rate to placebo/control. Interpretation- The current NMA suggests a potential role for treatments with brain-acting effect (for example, amitriptyline, acamprosate, and gabapentin) or anti-inflammation/anti-oxidant effect (for example, intra-tympanic dexamethasone injection plus oral melatonin) as the preferable effective treatments for tinnitus without specific or treatable origin

Вихретоковый анизотропный термоэлектрический первичный преобразователь лучистого потока

Представлена оригинальная конструкция первичного преобразователя лучистого потока, который может служить основой для создания приемника неселективного излучения с повышенной чувствительностью