Experiments on excitation and data processing of low-frequency vibroseis in permafrost area of the tibetan plateau

Few seismic exploration work was carried out in Tibetan Plateau due to the characteristics of alpine hypoxia and harsh environmental protection needs.Complex near surface geological conditions,especially the signal shielding and static correction of permafrost make the quality of seismic data is not ideal,the signal to noise ratio(SNR)is low,and deep target horizon imaging is difficult.These data cannot provide high quality information for oil and gas geological survey and structural sedimentary research in the area.To solve the issue of seismic exploration in Tibetan Plateau,this test used low frequency vibroseis wide-line and high-density acquisition scheme.In view of the actual situation of the study area,the terrain,the source and the diff erent observation system were simulated,and the processing technique was adopted to improve the quality of seismic data.Low-frequency components with a minimum of 1.5Hz of vibroseis ensure the deep geological target imaging quality in the area,the seismic profi le wave group is clear,and the SNR is relatively high,which can meet the needs of oil and gas exploration.Seismic data can provide the support for the development of oil and gas survey in the Tibet plateau.

Differential impact of aging and gender on lipid and lipoprotein profiles in a cohort of healthy Chinese Singaporeans

Aim： To evaluate the impact of age and gender on lipid and lipoprotein profiles and the burden of dyslipidemia in a cohort of healthy Chinese Singaporean. Methods： A total of 1 775 healthy Chinese, 536 men and 1 239 women aged between 30 and 70 years old were involved in the present study. Results： Gender differences in all lipid and lipoprotein levels were clearly evident. Singaporean Chinese men have significantly higher levels of total cholesterol （TC）, triglyceride （TG）, low density lipoprotein-cholesterol （LDL-C） and total cholesterol/high density lipoprotein-cholesterol （TC/HDL-C）, and lower levels of HDL-C than women. Although lipid and lipoprotein levels in men did not change in the different age groups, those in women, especially TC, LDL-C and TC/HDL-C, were significantly higher in older women （〉 50 years old） than corresponding levels in younger women （30-46 years old）. Furthermore, TG was significantly correlated with lipids and lipoproteins differently in men and women. If 100 mg/dL of LDL-C were to be adopted as the therapeutic cut-off level, then the burden of care will be huge as approximately 90% of both Chinese men and women have LDL-C greater than 100 mg/dL. Condusion： In light of the findings of the present study, we suggest that preventive measures to promote the reduction in risk of coronary heart disease （CHD） must address the high proportion of men and women with high LDL-C, and that these measures should take into account both the gender and age factors. For men, reduction of high cholesterol must start early in life, whereas for women, steps must be taken earlier to mitigate the anticipated sharp increase in risk, especially after menopause.

ANALYSIS OF SERUM LIPIDS IN PSORIASIS

Serum lipids were determined in 100 psoriatics and the results indicated (1) the incidences of hypercholesterolemia (9%) and hypertriglyceridemia (17%) in psoriatics were significantly higher than in controls; (2) the mean values of serum TC, LDL-C and TC/HDL-C in psoriatics were significantly higher as compared with normal healthy controls matched for sex and age; (3) serum TC, LDL-C and TG values were significantly higher in cases whose disease was progressive or whose lesions involved more than 20% of body surface area than in cases whose disease stationary or lesions less than 20%. As the incidences of hypertension and coronary heart disease were also significantly higher in psoriatics than in controls, the authors proposed that some integrated relationship would exist.

Fabrication of nano-crystalline W-Ni-Fe pre-alloyed powders by mechanical alloying technique

Nano-crystalline pre-alloyed powders of W-Ni-Fe were fabricated by high energy ball milling mechanical alloying (MA) technique. The change of appearances and the crystallite sizes of powders before and after high energy ball milling were investigated by XRD, TOPAS P software, SEM and EDS. The results show that the nano-crystalline pre-alloyed powders can be fabricated by 5 h high energy ball milling. During the MA process, the diffusion of W, Ni and Fe happens in the process of repeated welding and fracturing. As a result, nano-crystalline supersaturated solid solutions are formed. The crystallite sizes won't be refined after 10 h ball milling. The crystallite sizes of different compositions are almost the same under the same MA condition. Due to the toughening mechanism of rare earth element, the powders of 90W-4Ni-2Fe-3.8Mo-0.2RE alloy are seriously agglomerated after ball milling compared with the other alloys. It can be concluded that the optimal sintering temperature of 90W-4Ni-2Fe-3.8Mo-0.2RE pre-alloyed powders after 15 h mechanical alloying is 1 300-1 350 ℃.

Relationship between baseline monocyte to high-density lipoprotein cholesterol ratio and acute heart failure in postmenopausal women with acute coronary syndromes

Monocyte to high-density lipoprotein cholesterol ratio(MHR)becomes a novel cardiovascular prognostic predictor.The retrospective study was performed to investigate the relationship between MHR and acute heart failure(AHF)in postmenopausal women with acute coronary syndromes(ACS).Methods A cohort of 127 postmenopausal women diagnosed with ACS were enrolled.They underwent coronary angiography in Shantou Central Hospital(Shantou,China)from December 2014 and July 2016.The patients were assigned to two groups based on the admission MHR:low MHR group(MHR≤0.3677,n=51)and high MHR group(MHR>0.3677,n=76).The relationship between MHR and AHF was assessed by logistic regression analysis.Results Left ventricular ejection fraction of the low MHR group(64.2%±8.8%)was higher than that of the high MHR group(57.6%±12.9%)(P=0.002).Fractional shortening of the low MHR group(35.4%±6.4%)was higher than that of the high MHR group(30.6%±8.9%)(P=0.001).Hospitalization days of high MHR group(11.4±6.6 days)was longer than that of low MHR group(8.4±3.5 days)(P=0.006).Incidence of AHF(21%)in the high MHR group was higher than that in the low MHR group(4%)(P=0.008).MHR(OR:25.701,95%CI:3.099-213.143,P=0.003)could be an independent predictor for AHF in postmenopausal women with acute coronary syndromes.Conclusions The incidence of AHF in high baseline MHR group was higher than that in low baseline MHR group.This study demonstrated that high MHR level was a risk factor for AHF in postmenopausal women with ACS.

Dyslipidaemia among diabetic patients with ischemic stroke in a Chinese hospital

Background Dyslipidaemia is a potential independent The aim of this study was to investigate dyslipidaemia, with ischemic stroke in a Chinese hospital. risk factor for cerebrovascular disease in patients with diabetes. treatment and control of dyslipidaemia among diabetic patients Methods A total of 1046 type 2 diabetic patients were assigned to diabetes with （n=-522） and diabetes without stroke groups. The two groups were matched by gender, age and diabetes duration. Lipid and lipoprotein profile were measured. Serum level and control of lipids were assessed and classified according to American Diabetes Association （ADA） guidelines and an intensified low density lipoprotein-cholesterol （LDL-C） target recommended in Chinese dyslipidaemia control criteria. Results Diabetic patients suffering stroke displayed not only poorly-controlled lipid and lipoprotein profiles, including the significantly lower proportion of patients achieving intensified LDL-C target of 〈2.07 mmol/L （80 mg/dl）, and high density lipoprotein-cholesterol （HDL-C） target （14.4% vs 21.0%, P=0.005; 45.8% vs 51.9%, P=0.048 respectively）, but also less adherence to therapy prescribed for dyslipidaemia （30.8% vs 41.0%, P=0.001）, when compared with diabetic patients without stroke. For the diabetic women with stroke, situation of dyslipidaemia was worse, with significantly lower serum level of HDL-C and apoA1, higher LDL-C level and higher ratio of apoB/apoA1 when compared with diabetic counterparts without stroke. Conclusions Many diabetic patients with ischemic stroke remain uncontrolled for dyslipidaemia. Intensified LDL-C and overall lipid lowering clinical goals are potential precautions taken against ischemic stroke among diabetic patients in China.

Fatty acid desaturase 1 polymorphisms are associated with coronary heart disease in a Chinese population

Background A recent genome-wide association study in Caucasians revealed that three loci （rs174547 in fatty acid desaturase 1 （FADS1）, rs2338104 near mevalonate kinase/methylmalonic aciduria, cobalamin deficiency, cblB type （MVK/MMAB） and rs10468017 near hepatic lipase （LIPC）） influence the plasma concentrations of high-density lipoprotein-cholesterol （HDL-C） and triglycerides （TG）. However, there are few reports on the associations between these polymorphisms and plasma lipid concentrations in Chinese individuals. This study aimed to evaluate the associations between these three polymorphisms with HDL-C and TG concentrations, as well as coronary heart disease （CHD） susceptibility in Chinese individuals.