Analytical and numerical modeling of nonlinear lamb wave interaction with a breathing crack with low-frequency modulation.

To characterize fatigue crack, an analytical calculation and finite element (FE) simulation of Lamb wave propagating through the region of a breathing crack in a two-dimensional(2D) isotropic plate were studied. Contact surface boundary conditions between the two surfaces of the vertical crack were considered to study contact acoustic nonlinearity (CAN) from the breathing contact crack in conjunction with the modal decomposition method, Fourier transform, and variational principle-based algorithm. Reflection and transmission coefficients in the fundamental frequency and second harmonic frequency were calculated and analyzed quantitatively. Different ratios of incident wave amplitude to crack width were studied to calculate CAN results related to micro-crack width. In addition, a low-frequency (LF) vibration(10 Hz) excitation was introduced to perturb the free surface vertical crack to close, and an interrogating Lamb wave(1 MHz) was used to study crack-related CAN in different conditions for interpreting the modulation mechanism. The contact boundary conditions between two surfaces of vertical crack were set which were dynamically changed due to the low frequency modulation. The clapping effects when the crack closed due to the modulation of the contact boundary conditions between the crack surfaces were studied and analyzed to get the quantitative correlation between CAN and LF modulation. The results obtained from the analytical model were compared with those from the FE simulation, showing good consistency. Knowledge of these effects is essential to correctly gauge the severity of surface cracks in the plate, which can be spotlighted in its application to quantitative evaluation of micro fatigue cracks in structural health monitoring(SHM).

Effect of statins on pulmonary function in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis of randomized controlled trials.

Background: Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease, and its treatment is still controversial. Statins have been proven to have anti-inflammatory and immunomodulatory effects, but their effectiveness in the treatment of COPD is still unclear. We conducted this meta-analysis to more accurately evaluate the therapeutic effect of statins on COPD patients. Methods: Randomized controlled studies published in PubMed, Cochrane Library, Embase, Wiley Online Library, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases from inception to July 2022 were retrieved to evaluate the effect of statins on COPD patients. Two evaluators conducted literature screening based on inclusion and exclusion criteria, and conducted a bias risk assessment on them. Meta analysis was conducted using Stata17.0 statistical software. Results: A total of 1,463 patients from 10 studies were included. After statin treatment, the percentage of predicted forced expiratory volume in the first second (FEV1%pred) of COPD patients was improved [weighted mean difference (WMD): 7.89; 95% confidence interval (CI): 7.19-8.60; P<0.05], and the level of the inflammatory factor C-reactive protein (CRP) decreased (WMD: -0.63; 95% CI: -1.84, 0.58; P<0.05). The 6-minute walking distance (6MWD) of patients in the statin treatment group demonstrated a significant benefit (WMD: 26.27; 95% CI: 24.02-28.51; P<0.05). Compared to the placebo control group, statins significantly reduced COPD Assessment Test (CAT) (WMD: -2.45; 95% CI: -3.62, -1.27). Conclusions: Preliminary evidence suggests that statins may have a certain effect on improving lung function, reducing inflammatory factor levels, and improving clinical symptoms in COPD patients. However, due to the quality and quantity limitations of the included studies, these results need to be further verified through a larger, higher quality randomized controlled trial (RCT).

Characteristics of phenotypic antibiotic resistance of Helicobacter pylori and its correlation with genotypic antibiotic resistance: A retrospective study in Ningxia.

BACKGROUND: Geographic differences exist in the antibiotic resistance patterns of Helicobacter pylori. Personalized treatment regimens based on local or individual resistance data are essential. We evaluated the current status of H. pylori resistance in Ningxia, analyzed resistance-related factors, and assessed the concordance of phenotypic and genotypic resistance. METHODS: Strains were isolated from the gastric mucosa of patients infected with H. pylori in Ningxia and relevant clinical information was collected. Phenotypic antibiotic susceptibility assays (Kirby-Bauer disk diffusion) and antibiotic resistance gene detection (Sanger sequencing) were performed. RESULTS: We isolated 1955 H. pylori strains. The resistance rates of H. pylori to amoxicillin, levofloxacin, clarithromycin, and metronidazole were 0.9%, 42.4%, 40.4%, and 94.2%, respectively. Only five tetracycline-resistant and one furazolidone-resistant strain were identified. Overall, 3.3% of the strains were sensitive to all six antibiotics. Multidrug-resistant strains accounted for 22.9%, of which less than 20% were from Wuzhong. Strains isolated from women and patients with nonulcerative disease had higher rates of resistance to levofloxacin and clarithromycin. Higher rates of resistance to metronidazole, levofloxacin, and clarithromycin were observed in the older age group than in the younger age group. The kappa coefficients of phenotypic resistance and genotypic resistance for levofloxacin and clarithromycin were 0.830 and 0.809, respectively, whereas the remaining antibiotics showed poor agreement. CONCLUSION: H. pylori antibiotic resistance is severe in Ningxia. Therefore, furazolidone, amoxicillin, and tetracycline are better choices for the empirical therapy of H. pylori infection in this region. Host sex, age, and the presence of ulcerative diseases may affect antibiotic resistance of the bacteria. Personalized therapy based on genetic testing for levofloxacin and clarithromycin resistance may be a future direction for the eradication therapy of H. pylori infection in Ningxia.

Prevalence and risk factors of Helicobacter pylori infection in Ningxia, China: comparison of two cross-sectional studies from 2017 and 2022.

OBJECTIVES: Helicobacter pylori (H. pylori) infection causes a variety of intragastric and extragastric diseases. Despite its decreasing global prevalence, it remains a major public health problem in many developing countries. This study aimed to understand the prevalence of H. pylori infection and its risk factors in five cities of the Ningxia Hui Autonomous Region, an area with high incidence of gastric cancer. METHODS: Cross-sectional studies were conducted in Ningxia from 2017 and 2022, to detect the prevalence of H. pylori using the 14C urea breath test. All participants completed a questionnaire that included demographics, personal habits, household economic characteristics, and previous health status. Multiple logistic regression analyses were used to identify independent factors for H. pylori infection. RESULTS: Our findings demonstrated that the prevalence of H. pylori infection in Ningxia decreased significantly from 60.3% in 2017 to 43.6% in 2022, with an increase in public awareness rate from 35.9% in 2017 to 68.5% in 2022. The lowest infection rate was found in Zhongwei and highest in Guyuan. The prevalence of H. pylori infection was higher among Hui ethnicity, farmers, individuals living in rural areas, individuals with lower income, low education, and those who consumed less fruit. Gallbladder, respiratory, cardiovascular and autoimmune diseases were not associated with H. pylori infection. CONCLUSIONS: The prevalence of H. pylori in Ningxia decreased in the past five years. Ethnicity, location, occupation, income, education, and consumption of fruits were independent risk factors for H. pylori infection in Ningxia. It was not associated with extra-gastric disease.

A Survey of Helicobacter pylori Antibiotic-Resistant Genotypes and Strain Lineages by Whole-Genome Sequencing in China.

Antibiotic resistance is the most important factor leading to failed Helicobacter pylori eradication therapy, and personalized treatment based on antibiotic susceptibility is becoming increasingly important. To strengthen the understanding of antibiotic genotypic resistance of H. pylori and identify new antibiotic resistance loci, in this study, we identified phenotypic resistance information for 60 clinical isolates and compared the concordance of phenotypic and genotypic resistance using whole-genome sequencing (WGS). Clarithromycin and levofloxacin genotypic resistance was in almost perfect concordance with phenotypic resistance, with kappa coefficients of 0.867 and 0.833, respectively. All strains with the R16H/C mutation and truncation in rdxA were metronidazole resistant, with 100% specificity. For other genes of concern, at least one phenotypically sensitive strain had a previous mutation related to antibiotic resistance. Moreover, we found that the A1378G mutation of HP0399 and the A149G mutation of FabH might contribute to tetracycline resistance and multidrug resistance, respectively. Overall, the inference of resistance to clarithromycin and levofloxacin from genotypic resistance is reliable, and WGS has been very helpful in discovering novel H. pylori resistance loci. In addition, WGS has also enhanced our study of strain lineages, providing new ways to understand resistance information and mechanisms.

Be aware of the effects of glucocorticoids on SIADH: A case report.

RATIONALE: Hyponatremia is one of the most common electrolyte disorders in clinic. Due to the complicated etiology and the nonspecific clinical manifestations, the diagnosis of hyponatremia is a complicated process. A variety of clinical disorders can cause inappropriately increased antidiuretic hormone (ADH) secretion, leading to inappropriate water retention and consequent hyponatremia. The most common cause of hyponatremia in hospital inpatients is syndrome of inappropriate antidiuretic (SIADH). The action of glucocorticoid against pituitary posterior lobe can reduce the secretion of ADH. However, the effect of hormone on diuretic hormone during treatment has been less reported. PATIENT CONCERNS AND DIAGNOSIS: The patient in this case report was misdiagnosed as anterior pituitary hypofunction because of the long-term glucocorticoid therapy was effective in this patient, and the patient was finally diagnosed as SIADH after reassessment. The patient is a 76-year-old male with long-term symptomatic hyponatremia after traumatic brain injury (TBI). The patient has been consistently diagnosed as anterior pituitary hypofunction. Based on the diagnosis, glucocorticoid replacement therapy was administered. The serum sodium of the patient gradually increased to normal level after hydrocortisone intravenous injection but dropped again after switch to hydrocortisone oral administration. Through examination and analysis of the patient status during the five-time hospitalization, syndrome of inappropriate antidiuretic hormone (SIADH) was considered. INTERVENTIONS: Water intake limitation and oral furosemide and antisterone were administered after glucocorticoid therapy was stopped. OUTCOME: The serum sodium level of the patient gradually increased and maintained within normal range based on his clinical follow-up. LESSONS: For hyponatremia with effective glucocorticoid treatment, SIADH should still be excluded.

Aromatase excess syndrome in a Chinese boy due to a novel duplication at 15q21.2.

Background Aromatase excess syndrome (AEXS) is a rare autosomal dominant disorder caused by CYP19A1 overexpression. Clinical manifestations of AEXS include pre- or peri-pubertal gynecomastia, advanced bone age and compromised adult height. Case presentation Here we report an 8-year-old boy diagnosed with AEXS by chromosomal array that revealed a 1.1 Mb novel de novo duplication at 15q21.2, with a predicted final height of 157.4 cm. We prescribed letrozole and growth hormone (GH) to maximize his linear growth. Without further bone age advancement, his height increased from 137.7 cm to 144 cm after an 8-month treatment period. Conclusions We identified a novel duplication at 15q21.2 in AEXS, and found that aromatase inhibitor (AI) plus GH might provide a better growth-promoting approach for AEXS patients.

Direct Observation of Nanoscale Light Confinement without Metal.

Manipulation of light below the diffraction limit forms the basis of nanophotonics. Metals can confine light at the subwavelength scale but suffer from high loss of energy. Recent reports have theoretically demonstrated the possibility of light confinement below the diffraction limit using transparent dielectric metamaterials. Here, nanoscale light confinement (<λ/20) in transparent dielectric materials is shown experimentally through a luminescent nanosystem with rationally designed dielectric claddings. Theoretically, green light with a wavelength of 540 nm has a transmission of 98.8% when passing through an ultrathin NaYF4 /NaGdF4 superlattice cladding (thickness: 6.9 nm). Unexpectedly, the complete confinement of green emission (540 nm) by such an ultrathin dielectric cladding is directly observed. FDTD calculations are used to confirm that the ultrathin dielectric cladding has negligible influence on the transmission of propagating light, but extraordinary confinement of evanescent waves. This will provide new opportunities for nanophotonics by completely averting the use of metals.

Effect of FPZ, a total flavonoids ointment topical application from Pouzolzia zeylanica var. microphylla, on mice skin infections

ABSTRACT The present study was designed to investigate the effect of FPZ, a total flavonoids ointment topical application from Pouzolzia zeylanica var. microphylla (Wedd.) Masam, Urticaceae, on skin infections in mice. FPZ ointment anti-infective effect was investigated on Staphylococcus aureus-induced skin abscess and skin ulcers in mice by evaluating the variation in abscess volume, histopathology of skin tissue and healing rate. Secondary, it is topical anti-inflammatory activities on carrageenan-induced hind paw edema in mice was estimated. Besides, FPZ ointment fingerprint was performed by using ultra-performance liquid chromatography and FPZ ointment chemical constituents were isolated and identified by repeated column chromatograph and spectroscopic methods. The results revealed that FPZ ointment topical application at the concentration of 2.5-10% could attenuate skin abscess and ulcers and accelerate wound healing, as compared with control group treated with vehicle (p < 0.05). The histological analysis indicated that FPZ ointment acted via inflammation inhibition, granulation promotion and epidermis formation. Moreover, FPZ ointment effectively inhibited carrageenan-induced paw edema in a dose-dependent manner, especially 10% FPZ which showed superior activities in comparison with dexamethasone used as reference drug. FPZ ointment topical application showed a significant anti-infective effect against pyogenic bacterial skin infection in mice.

Prevalence of High-Risk Human Papillomavirus Infection in China: Analysis of 671,163 Human Papillomavirus Test Results From China's Largest College of American Pathologists-Certified Laboratory.

OBJECTIVES: This study on human papillomavirus (HPV) testing in China's largest independent laboratory accredited by the international Laboratory Accreditation Program of the College of American Pathologists extends previous reports on cervical screening test results from this Chinese facility. METHODS: A retrospective laboratory database search from 2007 to 2014 documented high-risk HPV test results using either Hybrid Capture 2 (HC2; Qiagen, Hilden, Germany) or multiplex polymerase chain reaction fluorescence testing (MPFT) methods. RESULTS: During the study period, HPV testing steadily increased, with 643,702 HC2 and 27,641 MPFT HPV tests performed. The mean ages of the tested women were 35.0 years using HC2 and 38.3 years using MPFT. The HC2 HPV-positive rate was 21.7%, significantly higher than 15.7% with MPFT (P < .0001), with bimodal peak incidence in adolescents and women aged 60 to 69 years. CONCLUSIONS: Use of HPV testing in cervical screening is increasing in China. HC2 HPV-positive rates around 20% in all age groups from more than 500,000 tested Chinese women are consistent with previous reports from China and significantly higher than published HC2 HPV-positive rates in populations with more widespread cervical screening. MPFT HPV-positive rates were slightly lower in every age group. The high HPV-positive rate likely reflects limited routine cervical screening and high cervical cancer incidence in China.