Dynamic crushing behaviors and enhanced energy absorption of bio-inspired hierarchical honeycombs with different topologies

In order to pursue good crushing load uniformity and enchance energy absorption efficiency of conventional honeycombs, a kind of bio-inspired hierarchical honeycomb model is proposed by mimicking the arched crab shell structures. Three bio-inspired hierarchical honeycombs(BHHs) with different topologies are designed by replacing each vertex of square honeycombs with smaller arc-shaped structures. The effects of hierarchical topologies and multi-material layout on in-plane dynamic crushings and absorbed-energy capacities of the BHHs are explored based on the explicit finite element(FE) analysis.Different deformation modes can be observed from the BHHs, which mainly depend upon hierarchical topologies and impact velocities. According to energy efficiency method and one-dimensional(1D) shock theory, calculation formulas of densification strains and plateau stresses for the BHHs are derived to characterize the dynamic bearing capacity, which is consistent well with FE results. Compared with conventional honeycombs, the crushing load efficiency and energy absorption capacity of the BHHs can be improved by changing the proper hierarchical topology and multi-material layout. These researches will provide theoretical guidance for innovative design and dynamic response performance controllability of honeycombs.

Association betweenITGA2 C807T polymorphism and gastric cancer risk

AIM： To evaluate the impact of the ITGA2 gene polymorphism on gastric cancer risk. METHODS： A hospital-based case-control study was conducted, including 307 gastric cancer patients and 307 age- and gender-matched control subjects. The genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism assay. RESULTS： The frequencies of the wild and variant genotypes in cases were significantly different from those of controls （P = 0.019）. Compared with individuals with the wild genotype CC, subjects with the variant genotypes （CT ＋ IT） had a significantly higher risk of gastric cancer （adjusted odds ratio = 1.57, 95% CI = 1.13-2.17, P = 0.007）. In stratified analyses, the elevated gastric cancer risk was especially evident in older individuals aged 〉 58 years, nonsmokers and rural subjects. Further analyses revealed that the variant genotypes were associated with poor tumor differentiation and adjacent organ invasion in the sub-analysis of gastric cancer patients. CONCLUSION： The ITGA2 gene C807T polymorphism may be associated with an increased risk of gastric cancer, differentiation and invasion of gastric cancer.

Impact of Tobacco Smoking on Health Care Utilization and Medical Costs in Chronic Obstructive Pulmonary Disease,Coronary Heart Disease and Diabetes

Objective To determine the impact of smoking on disease-specific health care utilization and medical costs in patients with chronic non-communicable diseases(NCDs).Methods Participants were middle-aged and elderly adults with chronic NCDs from a prospective cohort in China.Logistic regressions and linear models were used to assess the relationship between tobacco smoking,health care utilization and medical costs.Results Totally,1020 patients with chronic obstructive pulmonary disease(COPD),3144 patients with coronary heart disease(CHD),and 1405 patients with diabetes were included in the analysis.Among patients with COPD,current smokers(β:0.030,95%CI:−0.032-0.092)and former smokers(β:0.072,95%CI:0.014-0.131)had 3.0%and 7.2%higher total medical costs than never smokers.Medical costs of patients who had smoked for 21-40 years(β:0.028,95%CI:−0.038-0.094)and≥41 years(β:0.053,95%CI:−0.004β0.110)were higher than those of never smokers.Patients who smoked≥21 cigarettes(β:0.145,95%CI:0.051-0.239)per day had more inpatient visits than never smokers.The association between smoking and health care utilization and medical costs in people with CHD group was similar to that in people with COPD;however,there were no significant associations in people with diabetes.Conclusion This study reveals that the impact of smoking on health care utilization and medical costs varies among patients with COPD,CHD,and diabetes.Tobacco control might be more effective at reducing the burden of disease for patients with COPD and CHD than for patients with diabetes.

Ku80 gene G-1401T promoter polymorphism and risk of gastric cancer

AIM:To evaluate the possible relationship between the Ku80 gene polymorphism and the risk of gastric cancer in China.METHODS:In this hospital-based case-control study of gastric cancer in Jiangsu Province,China,we investigated the association of the Ku80 G-1401T (rs828907) polymorphism with gastric cancer risk.A total of 241 patients with gastric cancer and 273 age-and sexmatched control subjects were genotyped and analyzed by polymerase chain reaction-restriction fragment length polymorphism.RESULTS:The frequencies of genotypes GG,GT and TT were 65.6%,22.8% and 11.6% in gastric cancer cases,respectively,and 75.8%,17.6% and 6.6% in controls,respectively.There were significant differences between gastric cancer and control groups in the distribution of their genotypes (P=0.03) and allelic frequencies (P=0.002) in the Ku80 promoter G-1401T polymorphism.CONCLUSION:The T allele of Ku80 G-1401T may be associated with the development of gastric cancer.

Generation of domain-wall solitons in an anomalous dispersion fiber ring laser

We report experimental observations performed using a net anomalous dispersion Er-doped fiber ring laser without polarization-selective elements,highlighting the domain-wall solitary pulses generated under the incoherent polarization coupling.By adjusting the pump power and the polarization state appropriately,bright and dark solitons can stably co-exist in the cavity,both centered at 1562.16 nm with a 3-dB spectral width of -0.15 nm and a repetition rate of 3.83 MHz.Moreover,the 0.8 mm long thulium-doped fiber(TDF)facilitated the mode-locking and self-starting of the laser.This is the first demonstration of a laser being used to generate bright and dark solitons synchronously while using TDF as the saturable absorber(SA).Except possessing the all-fiber structure,the laser exhibits good stability,which may have a significant influence on improvement of the pulse-laser design,and may broaden practical applications in optical sensing,optical communication,and soliton multiplexed systems.

Two sequential surgeries in infant with multiple floor of the mouth dermoid cysts: A case report

BACKGROUND Multiple intraoral dermoid cysts of large magnitude generally appear in the second or third decade of life.They are rare in infants and are usually solitary.In this case,a large mass was identified in utero during prenatal exams.CASE SUMMARY We introduce a rare case on multiple dermoid cysts in the floor of the mouth of an infant who underwent two surgeries for this.Preoperative magnetic resonance imaging confirmed a large well-circumscribed cystic lesion that originated at the former midline region in the floor of the mouth in which a suspicious lesion of minute size was likely compressed by the bulkier mass and overlooked.Therefore,the infant underwent two surgeries by an intraoral approach within 9 mo.At 5 mo after the second operation,a routine follow-up ultrasound showed evidence of an additional cyst.No further surgery was planned because the tumor had no immediate effect.CONCLUSION This report demonstrates the importance of carefully analyzing preoperative imaging to avoid multiple operations for a seemingly isolated oral cyst.

Dynamic and quasi-static compressive performance of integral-forming aluminum foam sandwich

Strain rate sensitivity and deformation mechanism of integral-forming aluminum foam sandwich(IFAFS)under quasi-static and dynamic compression were investigated.Split Hopkinson pressure bar experiments with high-speed video cameras were conducted to analyze strain rate dependency and actual deformation mechanism of IFAFS.X-ray microtomography technique(Micro-CT)based on 3D finite element(FE)was used to study stress and plastic strain contours of IFAFS sample and to predict stress distribution and deformation history under both dynamic and quasi-static loadings.Micro-inertia effect of typical cell structures was quantitatively analyzed by FE simulation.The results showed that IFAFS is sensitive to strain rate where the deformation mode under dynamic loading is different from that observed under quasi-static loading.With strain rate increasing,good metallurgical bonding of face sheet and foam core layer contributed to improving the elastic modulus and peak stress of IFAFS.Furthermore,finite element model confirmed that micro-inertia effect of IFAFS can be ignored during dynamic loading.

Perfluorinated compounds in blood of textile workers and barbers

12 perfluorinated compounds（PFCs） in human blood from workers in a textile mill in Shandong province and several barbershops in Tianjin were analyzed in this study. It was found that perfluorooctanesulfonate（PFOS） and perfluorooctanoate（PFOA） were the most prominent PFCs, with average concentrations of 5.73 mg/L and 5.46 mg/L for textile workers, and 2.55 mg/L and 2.84 mg/L for barbers.PFOS and perfluorohexanesulfonate（PFHxS） concentrations revealed a positive correlation in blood samples（p 〈 0.01）, and concentrations among PFOS, perfluorononanoic acid（PFNA） and perfluorodecanoic acid（PFDA） also revealed positive correlations（p 〈 0.01）. The influence of gender and age on PFC concentration in blood was also investigated, and the results showed that there was no statistically significant difference between the male and female samples, as well as in samples from people with different ages. Generally speaking, the textile workers

Diagnosis of Malignancy of Adult Mediastinal Tumors by Conventional and Transesophageal Echocardiography

Background： Transesophageal echocardiography （TEE） is a well-established method for detecting and diagnosing heart tumors. In contrast, its role in assessing the presence, growth and evidence of malignant tumors originating from mediastinal sites remains unclear. The aim of this study was to compare the diagnostic impact of TEE and transthoracic echocardiography （TTE） for determining the localization, growth and malignancy of adult mediastinal tumors （MTs）. Methods： In a prospective and investigator-blinded study, we evaluated 144 consecutive patients with MT lesions to assess the diagnostic impact of TEE and TTE for detecting the presence of tumors spreading both inside and outside of the heart and for determining infiltration and invasion using pathological examination results as a reference. Results： All tumor lesions were diagnosed and carefully evaluated by biopsy. Biopsy revealed malignant tumors in 79 patients and benign tumors in 65 patients. When compared to histological findings, TEE predicted malignancy from the presence of tumors spreading both inside and outside of the heart and from infiltration and invasion in 49/79 patients （62.0%）. TTE predicted malignancy in only 8/79 patients （10.1%, P 〈 0.005）. TEE visualized tumor lesions in 130 patients （90.3%） while the TTE visualized tumor lesions in 110 patients （76.4%） and was less effective at detecting MT lesions （P 〈 0.001 ）. TTE and TEE could detect anterior MTs and adequately verified MTs （P 〉 0.05）： TEE detected medium MTs better than TTE （P 〈 0.001 ）. Conclusions： TEE is effective and superior to TTE for predicting the localization and growth of MTs as well as for accessing evidence of tumor malignancy. TTE and TEE were able to detect anterior MTs; TEE was able to detect medium MT better than TTE.