Renal resistive index measurements by ultrasound in patients with liver cirrhosis:Magnitude and associations with renal dysfunction

BACKGROUND The hemodynamic alterations seen in liver cirrhosis lead to renal vasoconstriction,ultimately causing acute kidney injury(AKI).The renal resistive index(RRI)is the most common Doppler ultrasound variable for measuring intrarenal vascular resistance.AIM To evaluate the association of the RRI with AKI in patients with liver cirrhosis and to identify risk factors for high RRI.METHODS This was a prospective observational study,where RRI was measured using Doppler ultrasound in 200 consecutive hospitalized patients with cirrhosis.The association of RRI with AKI was studied.The receiver operating characteristic(ROC)curve analysis was utilized to determine discriminatory cut-offs of RRI for various AKI phenotypes.Multivariate analysis was conducted to determine the predictors of high RRI.RESULTS The mean patient age was 49.08±11.68 years,with the majority(79.5%)being male;the predominant etiology of cirrhosis was alcohol(39%).The mean RRI for the study cohort was 0.68±0.09,showing a progressive increase with higher Child-Pugh class of cirrhosis.Overall,AKI was present in 129(64.5%)patients.The mean RRI was significantly higher in patients with AKI compared to those without it(0.72±0.06 vs 0.60±0.08;P<0.001).A total of 82 patients(41%)had hepatorenal syndrome(HRS)-AKI,29(22.4%)had prerenal AKI(PRA),and 18(13.9%)had acute tubular necrosis(ATN)-AKI.The mean RRI was significantly higher in the ATN-AKI(0.80±0.02)and HRS-AKI(0.73±0.03)groups than in the PRA(0.63±0.07)and non-AKI(0.60±0.07)groups.RRI demonstrated excellent discriminatory ability in distinguishing ATN-AKI from non-ATN-AKI(area under ROC curve:93.9%).AKI emerged as an independent predictor of high RRI(adjusted odds ratio[OR]:11.52),and high RRI independently predicted mortality among AKI patients(adjusted OR:3.18).CONCLUSION In cirrhosis patients,RRI exhibited a significant association with AKI,effectively differentiated between AKI phenotypes,and predicted AKI mortality.

Comparison of resistive index and shear-wave elastography in the evaluation of chronic kidney allograft dysfunction

BACKGROUND Detection of early chronic changes in the kidney allograft is important for timely intervention and long-term survival.Conventional and novel ultrasound-based investigations are being increasingly used for this purpose with variable results.AIM To compare the diagnostic performance of resistive index(RI)and shear wave elastography(SWE)in the diagnosis of chronic fibrosing changes of kidney allograft with histopathological results.METHODS This is a cross-sectional and comparative study.A total of 154 kidney transplant recipients were included in this study,which was conducted at the Departments of Transplantation and Radiology,Sindh Institute of Urology and Transplantation,Karachi,Pakistan,from August 2022 to February 2023.All consecutive patients with increased serum creatinine levels and reduced glomerular filtration rate(GFR)after three months of transplantation were enrolled in this study.SWE and RI were performed and the findings of these were evaluated against the kidney allograft biopsy results to determine their diagnostic utility.RESULTS The mean age of all patients was 35.32±11.08 years.Among these,126(81.8%)were males and 28(18.2%)were females.The mean serum creatinine in all patients was 2.86±1.68 mg/dL and the mean estimated GFR was 35.38±17.27 mL/min/1.73 m2.Kidney allograft biopsy results showed chronic changes in 55(37.66%)biopsies.The sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)of SWE for the detection of chronic allograft damage were 93.10%,96.87%%,94.73%,and 95.87%,respectively,and the diagnostic accuracy was 95.45%.For RI,the sensitivity,specificity,PPV,and NPV were 76.92%,83.33%,70.17%,and 87.62%,respectively,and the diagnostic accuracy was 81.16%.CONCLUSION The results from this study show that SWE is more sensitive and specific as compared to RI in the evaluation of chronic allograft damage.It can be of great help during the routine follow-up of kidney transplant recipients for screening and early detection of chronic changes and selecting patients for allograft biopsy.

Central retinal artery resistive index and optical coherence tomography in assessment of glaucoma progression

AIM: To assess the relation between central retinal artery(CRA) resistive index(RI) and retinal nerve fiber thickness measured by optical coherence tomography(OCT) in assessment of disease progress in cases of open angle glaucoma.METHODS: Twenty-three patients with diagnosed open angle glaucoma were included in this study. They were examined by colored duplex ultrasonography of CRA with estimation of RI of CRA and ophthalmic artery(OA)with estimation of CRA/OA RI ratio as well as OCT measurement of the average retinal nerve fiber layer(RNFL) thickness in order to assess the disease progress.RESULTS: There was strong inverse relation between the increased RI in CRA as well as the increased CRA/OA RI ratio and the decrease in average RNFL thickness in cases of open angle glaucoma.CONCLUSION: Assessment of CRA RI can indirectly assess the vascular changes associated with glaucoma and can assess the degree of retinal atrophy helping in evaluating prognosis thus guiding the choice of treatment.

Deferred revascularization in diabetic patient according to combined invasive functional and intravascular imaging data:A case report

BACKGROUND Invasive functional evaluation by fractional flow reserve(FFR)is considered as a gold standard for the evaluation of intermediate coronary stenosis.However,in patients with diabetes due to accelerated progression of atherosclerosis the outcome may be worse even in the presence of negative functional testing.CASE SUMMARY We present a case of 55-year-old male diabetic patient who was admitted for chest pain.Diagnostic coronary angiography disclosed 2 intermediate stenoses of the obtuse marginal branch with no evidence of restenosis on previously implanted stent.Patient undergone invasive functional testing of intermediate lesion with preserved FFR(0.88),low coronary flow reserve(1.2)and very high index of microvascular resistance(84).Due to discrepancy in invasive functional parameters,intravascular imaging with optical coherence tomography showed fibrotic stenoses without signs of thin-sup fibroatheroma.Because of the preserved FFR and no signs of vulnerable plaque,the interventional procedure was deferred and the patient continued with optimal medications.CONCLUSION Combined functional and anatomic imaging of intermediate coronary stenosis in diabetic patients represent comprehensive contemporary decision pathway in the management of the patients.

Comparison of Ultrasound Blood Flow Characteristics of the Lower Limb in Diabetics with Early-Stage Peripheral Artery Disease and Non-Diabetic Controls

The aim of this study was to compare lower limb blood flow in asymptomatic diabetic patients with early-stage peripheral artery disease (PAD) and non-diabetic controls using duplex ultrasound parameters. This was a comparative cohort study of lower limb blood flow in 35 Black-African diabetic patients (25 females and 10 males with early-stage PAD median age 54 [IQR, 47 - 61] years;median HbA1c 6.3 [IQR, 5.7 - 8.0]%;BMI 29.2 ± 6.7;ABI 1.1 ± 0.1) and 36 non-diabetic controls (28 females and 8 males;median age 54 [IQR, 47 - 61] years;median HbA1c 6.3 [IQR, 5.7 - 8.0] %, BMI 29.2 ± 6.7;ABI 1.1 ± 0.1). Peak systolic velocity (PSV), pulsatility index (PI) and resistive index (RI), were utilised to compare blood flow in the popliteal arteries (PA), anterior tibial arteries (ATA) and posterior tibial arteries (PTA) in addition to ankle brachial index. All the ultrasound parameters showed good (ICC ≥ 0.7;0.50 - 0.85, 95% CI) to excellent (ICC = 1.0;1.0 - 1.0, 95% CI) reliability within groups as well as acceptable variability () other than pulsatility index of the anterior tibial artery within diabetic patients (11.1% CV). PSV, RI and PI were significantly and meaningfully higher (P;d ≥ 0.33), in diabetic patients compared to non-diabetic controls except for PI - PTA (P = 0.72;d = 0.11). Differences in PSV and RI highlighted the effects of early-stage PAD on lower limb blood flow of diabetic patients. In contrast, the effects of early-stage PAD on blood flow were not demonstrated in the PTA and ATA of diabetic patients by PI.

Cardiovascular Function during First 24 Hours after Off-Pump and On-Pump CABG—A Prospective Observational Comparative Study

Purpose: Myocardial revascularization by coronary artery bypass grafting (CABG) in ischemic heart disease patients has direct impact on hemodynamic parameters in the immediate post-operative period. The peri-operative cardiovascular functioning is an important determinant for outcome of surgery. In On-Pump CABG (ONCAB), the cardiopulmonary bypass has a negative effect on myocardium. Off-Pump CABG (OPCAB) avoids the effect of CPB but complete revascularization with difficult positioning of heart is technically demanding. This study is aimed to compare the cardiovascular functioning in the immediate post-operative period after OPCAB and ONCAB. Methods: Total 106 patients were operated for CABG from January 2015 to June 2016, of which 75 patients were operated for OPCAB and 31 patients were operated for ONCAB. For the comparison, hemodynamic parameters were measured during anesthesia before surgery, postoperatively after 1 and 4 hours (h) in the ICU, and in the morning after surgery, approximately after 20 h. Results: The time-dependent rise of hemodynamic parameters like Cardiac Output (CO), Cardiac Index (CI), Stroke volume (SV) and Left Ventricular Stroke Work Index (LVSWI) in the immediate post-operative hours (1 h and 4 h) are more predominant in OPCAB group than ONCAB group although the difference is eliminated mostly at 20 h. The better peripheral vasodilation after OPCAB causes immediate fall of Systemic Vascular Resistance Index (SVRI) after OPCAB. Conclusion: Better cardiovascular functioning immediately after OPCAB than ONCAB may be important for better hemodynamic stability. The difference is however eliminated after 24 hours indicating little significance in long term outcome.

Numerical simulation of rock electrical properties based on digital cores

In this paper, we obtained three dimensional digital cores using X-ray CT to describe the rock microstructure and applied the open morphology algorithm to simulate oil and formation water distribution in the pore space at different water saturations during the oil-displacing water flood process. The resistivity, formation factor, and resistivity index of rocks were calculated using the finite element method （FEM） and we studied the effect of rock wettability on electrical properties. The numerical simulation results indicate that the simulated formation factor and resistivity index of the water wet rock agrees well with experiments over the whole range of water saturation and extends the traditional resistivity experiment. The rock wettablilty has a large influence on the rock resistivity index. The resistivity and saturation exponent of oil wet rock are obviously larger than three of water wet rock.

Resistance Evaluation of Capsicum spp. Germplasm to Meloidogyne incognita

[Objective] This study aimed to screen out hot pepper germplasms highly resistant to Meloidogyne incognita, thereby providing resistant resources for hot pep- per breeding. [Method] Comprehensive analysis combining cluster analysis and sub- ordinate function was conducted through determining related resistance indexes of 67 hot pepper germplasms 50 days after inoculated with M. incognita. [Result] The effects of M. incognita on related resistance indexes were significantly different am- ong the hot pepper germplasms. Egg index and gall index had abundant genetic variation with variation coefficients of 143.16% and 118.95%, respectively. Based on the gall indexes, cluster analysis of hot pepper germplasms was performed. The 67 hot pepper germplasms were divided into 4 groups （resistant, moderately resistant, susceptible and high susceptible）. The resistance intensity of the hot pepper germplasms were ranked according to the sum of subordinate function values of various resistance indexes. The total function values of Rela 2 and L506M were the largest （2.00）, indicating that these two germplasms were immune to M. incognita. The total function values of L287-2, L522-1M, L504M, L515-2, 13SM100-1, L512M, L292-1, L319, L316, L317, 13SM87-1 and Rela 5 were larger than 1.95, indicating that these germplasms were highly resistant to M. incognita. [Conclusion] This study could provide certain resistant resources for resistance breeding of hot pepper to M. incognita.

Effects of intermittent fasting on health markers in those with type 2 diabetes:A pilot study

AIMTo determine the short-term biochemical effects and clinical tolerability of intermittent fasting (IF) in adults with type 2 diabetes mellitus (T2DM).METHODSWe describe a three-phase observational study (baseline 2 wk, intervention 2 wk, follow-up 2 wk) designed to determine the clinical, biochemical, and tolerability of IF in community-dwelling volunteer adults with T2DM. Biochemical, anthropometric, and physical activity measurements (using the Yale Physical Activity Survey) were taken at the end of each phase. Participants reported morning, afternoon and evening self-monitored blood glucose (SMBG) and fasting duration on a daily basis throughout all study stages, in addition to completing a remote food photography diary three times within each study phase. Fasting blood samples were collected on the final days of each study phase.RESULTSAt baseline, the ten participants had a confirmed diagnosis of T2DM and were all taking metformin, and on average were obese [mean body mass index (BMI) 36.90 kg/m2]. We report here that a short-term period of IF in a small group of individuals with T2DM led to significant group decreases in weight (-1.395 kg, P = 0.009), BMI (-0.517, P = 0.013), and at-target morning glucose (SMBG). Although not a study requirement, all participants preferentially chose eating hours starting in the midafternoon. There was a significant increase (P < 0.001) in daily hours fasted in the IF phase (+5.22 h), although few attained the 18-20 h fasting goal (mean 16.82 ± 1.18). The increased fasting duration improved at-goal (< 7.0 mmol/L) morning SMBG to 34.1%, from a baseline of 13.8%. Ordinal Logistic Regression models revealed a positive relationship between the increase in hours fasted and fasting glucose reaching target values (χ2 likelihood ratio = 8.36, P = 0.004) but not for afternoon or evening SMBG (all P > 0.1). Postprandial SMBGs were also improved during the IF phase, with 60.5% readings below 9.05 mmol/L, compared to 52.6% at baseline, and with less glucose variation. Neither insulin resistance (HOMA-IR), nor inflammatory markers (C-reactive protein) normalized during the IF phase. IF led to an overall spontaneous decrease in caloric intake as measured by food photography (Remote Food Photography Method). The data demonstrated discernable trends during IF for lower energy, carbohydrate, and fat intake when compared to baseline. Physical activity, collected by a standardized measurement tool (Yale Physical Activity Survey), increased during the intervention phase and subsequently decreased in the follow-up phase. IF was well tolerated in the majority of individuals with 6/10 participants stating they would continue with the IF regimen after the completion of the study, in a full or modified capacity (i.e., every other day or reduced fasting hours).CONCLUSIONThe results from this pilot study indicate that short-term daily IF may be a safe, tolerable, dietary intervention in T2DM patients that may improve key outcomes including body weight, fasting glucose and postprandial variability. These findings should be viewed as exploratory, and a larger, longer study is necessary to corroborate these findings.

Diagnostic value of different color ultrasound diagnostic method in endometrial lesions

BACKGROUND Endometrial lesions include endometrial cancer and inferior fibroids.Among them,endometrial cancer as a malignant tumor seriously endangers the life and health of patients.Ultrasonography is an important means of diagnosing female reproductive system diseases,and it is of critical value for the early diagnosis of endometrial cancer.However,different ultrasound inspection programs have achieved different results.It is of great significance to choose a suitable inspection program.AIM To explore the diagnostic efficacy of different ultrasonic examination methods in clinical endometrial lesions.METHODS The 140 patients with endometrial lesions who were treated in our hospital from April 2018 to October 2019 were used as the research subjects.All patients underwent transvaginal color ultrasound and transabdominal color ultrasound.We compared the diagnostic coincidence and image display effects of the two different examination methods,and the endometrial thickness,blood flow,uterine effusion and resistance index of different diseases were observed by transvaginal color ultrasound.RESULTS The diagnostic coincidence rate of all types of diseases of transvaginal color ultrasound was significantly higher than that of transabdominal color ultrasound(P=0.001,0.005,0.001 and 0.001).In addition,the excellent and good rate of image display of transvaginal color ultrasound was higher than that of transabdominal color ultrasound(P=0.001).There were significant differences in endometrial thickness in patients with different types of endometrial lesions through the transvaginal color examination(P=0.001).The incidence rate of uterine effusion in patients with endometrial carcinoma was significantly higher than that in patients with other types of endometrial lesions(P=0.001),and the rate of the blood flow was the highest(P=0.001).The comparison of blood flow resistance index indicated that the blood flow resistance index in endometrial cancer patients was the lowest,which shows that the difference was statistically significant(P=0.001).CONCLUSION The overall diagnostic efficacy of transvaginal color ultrasound in the clinical diagnosis of endometrial lesions is better than that of transabdominal color ultrasound,which held higher diagnostic coincidence rate and image display effect.There were significant differences in the thickness of the endometrium and the blood flow in different types of lesions.

Relationship Between Coleoptile Length and Drought Resistance and Their QTL Mapping in Rice

By using a set of recombinant inbred line （RIL） population involving in 195 lines derived from a cross of Zhenshan 97B （lowland variety） and IRAT109 （upland variety）, the correlation analysis between coleoptile length （CL） and drought resistance index （DRI） and their QTL identification were conducted. There existed a significantly positive relationship between CL and DRI with the correlation coefficient of 0.2206＊＊ under water stress conditions. Under normal and water stress conditions, a total of eleven and four QTLs for CL and DRI, respectively, were detected on chromosomes 1,2, 4, 5, 6, 7, 9, 11 and 12 by using a linkage map including 213 SSR markers, which explained 4.84% to 22.65% of phenotypic variance. Chromosomes 1 and 9 possessing the QTLs for DRI harbored simultaneously QTLs for CL, and qCL9 shared the same chromosome location with qDR19 （RM160-RM215）. Comparing the QTLs related to drought resistance in other studies, QTLs for CL and DRI were located in the same or adjacent marker interval as those related to root traits, such as number, dry weight, depth, and length of root. Moreover, sixteen and three pairs of epistatic loci for CL and DRI were found, which accounted for 56.17% and 11.93% of the total variation in CL and DRI, respectively.

The Study of Ovarian Artery Hemodynamics in Patients with Infertility by Color Doppler Energy

Seventy four cases of infertility were examined to study the hemodynamics of the bilateral ovarian arteries at 21st day during the corpus luteum phase by color Doppler energy(CDE) and color Doppler flow imaging (CDFI). All the patients were verified by laparoscopy, fallopian tube patency examination and ovarian function test. Twenty two healthy women served as controls. The results showed that the difference of resistance index(RI)and pulsatility index (PI) of bilateral ovarian arteries between the infertility and the normal controls had statistical significance ( P <0.01), and the PI showed negative correlation with the thickness of endometrium (left side: r =0.724, P <0.01; right side: r =0.756, P <0.01). The results also showed that CDE was more sensitive than CDFI in displaying the ovarian arteries. It could be concluded that the elevated resistance of ovarian artery during the corpus luteum phase was one of the important factors that resulted in infertility.

Role of imaging in the evaluation of renal dysfunction in heart failure patients

Heart failure and kidney disease share common pathophysiological pathways which can lead to mutual dysfunction,known as cardiorenal syndrome.In heart failure patients,renal impairment is related to hemodynamic and nonhemodynamic factors.Both decreased renal blood flow and renal venous congestion due to heart failure could lead to impaired renal function.Kidney disease and worsening renal function are independently associated with poor prognosis in heart failure patients,both in acute and chronic clinical settings.The aim of this review is to assess the role of renal imaging modalities in the evaluation and management of heart failure patients.Renal imaging techniques could complete laboratory data,as estimated glomerular filtration rate,exploring different pathophysiological factors involved in kidney disease and adding valuable information about renal structure and function.In particular,Doppler examination of arterial and venous hemodynamics is a feasible and non invasive technique,which has proven to be a reliable method for prognostic stratification in patients with cardiorenal syndrome.The renal resistance index,a measure related to renal hemodynamics,can be calculated from the Doppler evaluation of arterial flow.Moreover,the analysis of Doppler venous flow patterns can integrate information from the arterial study and evaluate renal congestion.Other imaging modalities are promising,but still confined to research purposes.

Is spleen circulation impaired in systemic sclerosis and what is the role of liver fibrosis?

AIM:To investigate the spleen vascular involvement and the presence of liver fibrosis in a population of subjects with established systemic sclerosis(SSc).METHODS:In a cross-sectional fashion,17 patients with SSc were compared with 18 patients suffering from hepatitis C virus(HCV) -related liver cirrhosis,grade A and B Child-Pugh classification.Eighteen non elderly subjects,apparently healthy,were used as the control group.Splenic artery resistivity index(SARI) at doppler ultraSound,transient elastography of liver and nailfold capillaroscopy were the main outcomes.RESULTS:Transient elastography values of SSc patients were similar to those of controls;5.2±1.1 vs 4.5 ±1,(P=0.07).Median Alanine amino transferase(ALT) concentrations of cirrhotic patients were greater than those of controls and SSc patients,i.e.66.5(36-89) U/L vs 29(22-34) U/L and 31(22-41) U/L,respectively,(P =0.005).SARI determinations in cirrhotic patients,although significantly higher than those found in controls and SSc patients,showed some degree of overlap with SSc patients,i.e.0.59 vs 0.52 and 0.57,respectively,(P =0.04).Mean systolic blood pressure was significantly higher in SSc patients than in cirrhotics and controls,i.e.142 mmHg vs 128.2 mmHg and 127 mmHg,respectively,(P=0.005).Mean diastolic blood pressure behaved in a similar fashion,i.e.84 mmHg vs 72.2 mmHg and 76.9 mmHg(P=0.005).Nailfold Capillaroscopy grades and diastolic blood pressure values correlated well with SARI results.CONCLUSION:An enhanced resistivity of the splenic artery was found in patients suffering from SSc;they did not have evidence of splenomegaly as well as no liver fibrosis or any other form of liver damage.

Increased Circulating Myostatin in Patients with Type 2 Diabetes Mellitus

The changes of plasma myostatin levels in patients with type 2 diabetes mellitus(T2D) and their clinical correlation were investigated.We recruited 43 T2D patients and 20 age-matched healthy subjects.Plasma myostatin,lipid and glucose,and serum insulin were determined.T2D patients showed significantly higher fasting plasma glucose(FPG),serum insulin and triglyceride levels,and lower high-density lipoprotein levels than normal control subjects(P<0.01).Mean plasma myostatin level in T2D patients and health controls was(66.5±17.8) and(46.2±13.8) ng/mL,respectively.An unpaired t test showed that the increase of myostatin in the T2D patients was significant(P<0.001).In both healthy control and T2D groups,the female subjects showed higher myostatin levels than the male subjects.In the T2D patients,plasma level of myostatin was negatively correlated with body mass index(BMI,r=-0.42,P<0.01) and FPG(r=-0.51,P<0.01),but positively correlated with insulin resistance index(HOMA-IR,r=0.48,P<0.01).Up-regulation of plasma myostatin in the T2D patients and its correlation with BMI,FPG and blood insulin sensitivity suggests that plasma myostatin may be implicated in the pathogenesis of T2D and thus presented as a therapeutic target for treating the disease.Furthermore,circulating myostatin levels may be used as a biomarker for the disease.

Prognostic value of hemodynamic indices in patients with sepsis after fluid resuscitation

BACKGROUND Sepsis usually causes hemodynamic abnormalities.Hemodynamic index is one of the factors to identify the severity of sepsis and an important parameter to guide the procedure of fluid resuscitation.The present study investigated whether the assessment of hemodynamic indices can predict the outcomes of septic patients undergoing resuscitation therapy.AIM To evaluate the prognostic value of hemodynamic indices in patients with sepsis after fluid resuscitation.METHODS A retrospective study was conducted in 120 patients with sepsis at Hainan General Hospital/Hainan Affiliated Hospital of Hainan Medical University between October 2016 and October 2019.All patients were treated with sodium chloride combined with dextran glucose injection for fluid resuscitation.Patients’hemodynamic parameters were monitored,including heart rate(HR),cardiac index(CI),systemic vascular resistance index(SVRI),mean arterial pressure(MAP),central venous pressure(CVP),and central venous oxygen saturation.The prognostic value of hemodynamic indices was determined based on the prognosis status.RESULTS During fluid resuscitation,86 patients developed septic shock and 34 did not.Ninety-nine patients survived and 21 patients died at 28 d after the treatment.Heart rate,CI,mean arterial pressure,SVRI,and CVP were higher in patients with septic shock and patients who died from septic shock than in non-shock patients and patients who survived,and central venous oxygen saturation was lower in patients with shock and patients who died than in non-shock patients and thesurvivors (P < 0.05). When prognosis was considered as a dependent variable andhemodynamic parameters was considered as independent variables, the results ofa logistic regression analysis showed that CI, SVRI, and CVP were independentrisk factors for septic shock, and CI was an independent risk factor for 28-dmortality (P < 0.05).CONCLUSIONHemodynamic indices can be used to evaluate the prognosis of septic patientsafter fluid resuscitation.

Evaluation method of cracking resistance of lightweight aggregate concrete

The cracking behavior of lightweight aggregate concrete(LWAC) was investigated by mechanical analysis, SEM and cracking-resistant test where a shrinkage-restrained ring with a clapboard was used. The relationship between the ceramsite type and the cracking resistance of LWAC was built up and compared with that of normal-weight coarse aggregate concrete(NWAC). A new method was proposed to evaluate the cracking resistance of concrete, where the concepts of cracking coefficient ζt(t) and the evaluation index Acr(t) were proposed, and the development of micro-cracks and damage accumulation were recognized. For the concrete with an ascending cracking coefficient curve, the larger Acr(t) is, the lower cracking resistance of concrete is. For the concrete with a descending cracking coefficient curve, the larger Acr(t) is, the stronger the cracking resistance of concrete is. The evaluation results show that in the case of that all the three types of coarse aggregates in concrete are pre-soaked for 24 h, NWAC has the lowest cracking resistance, followed by the LWAC with lower water absorption capacity ceramsite and the LWAC with higher water absorption capacity ceramsite has the strongest cracking resistance. The proposed method has obvious advantages over the cracking age method, because it can evaluate the cracking behavior of concrete even if the concrete has not an observable crack.

Study on relationship between perifollicular blood flow and in vitro fertilization-embryo transfer

Objective：To study the relationship between perifollicular blood flow and follicule development, oocyte maturing rate, fertilizing rate, cleaving rate, embryo quality and the outcomes of embryo transfer. Methods： The samples were selected from 66 suffers who underwent in vitro fertilization（IVF）or intracytoplasmic sperm injection（ICSl）. Eeach patients＇ perifollicular blood flow（diameter ≥ 12mm ）was estimated on the day of human chorionic gonadotropin（HCG）administration. Results：Among 66 cycles, 26（39.4%） cycles resulted in pregnancy, perifollicular blood flow resistance index（Rl）, peak systolic velocity/end diastasis velocity（S/D） of non-pregnant group was significantly higher than that of the pregnant group （P 〈 0.004）. When RI 〈 0.49, the pregnancy rates, fecundation rates, fertilization rates, metaphase numbers for the of second meiosis oocytes increased evidently （P 〈 0.05）, but there were no statistical difference in gonadotropin dosage, cycle frequency, infertility years, ages, estradiol（E2）on the day of HCG administration, numbers of oocyet retrieved and high-quality embryo rates （P 〉 0.05 ）. There were no statistical difference between non-pregnant group and pregnant group in S and D （P 〉 0.05 ）. There was no correlation between periFollicular blood flow RI and follicular diameter by linear regression analysis. Conclusion：Our study shows that perifollicular blood flow RI and S/D are effective indices of predicting the pregnancy outcome of IVF-ET.

Coronary physiology assessment in the catheterization laboratory

Physicians cannot rely solely on the angiographic appearance of epicardial coronary artery stenosis when evaluating patients with myocardial ischemia. Instead, sound knowledge of coronary vascular physiology and of the methods currently available for its characterization can improve the diagnostic and prognostic accuracy of invasive assessment of the coronary circulation, and help improve clinical decision-making. In this article we summarize the current methods available for a thorough assessment of coronary physiology.

Gas hydrate saturation model and equation for logging interpretation

Since gas hydrate exists in three different forms at the same time such as pore filling,particle support and separate stratification,the calculation method of hydrate saturation using traditional shaly sand formation interpretation models is equivalent to considering only the simple case that hydrate exists as pore filling,and does not consider other complex states.Based on the analysis of hydrate resistivity experimental data and the general form of the resistivity-oil(gas)saturation relationship,the best simplified formula of hydrate saturation calculation is derived,then the physical meaning of the three items are clarified:they respectively represent the resistivity index-saturation relationship when hydrate particles are completely distributed in the pores of formation rocks,supported in the form of particles,and exist in layers,corresponding quantitative evaluation method of hydrate saturation is built.The field application shows that the hydrate saturation calculated by this method is closer to that obtained by sampling analysis.At the same time,it also provides a logging analysis basis for the effective development after hydrate exploration.