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Very limited information is available on body burdens and environmental levels of dioxins and dioxin-like PCBs (dl-PCBs) in mainland China. In the current studies, human milk samples were collected from 30 breastfeeding mothers in Shijiazhuang city (industrialized) and 11 in the Tanshan countryside (agricultural) of Hebei Province in northern China. An additional 20 samples were obtained from mothers in Tokyo, Japan. PCDDs, PCDFs, and dl-PCBs in human milk were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry. Our results show that arithmetic means for body burdens of PCDDs/Fs and dl-PCBs in Hebei were 3.6 and 1.9 pg TEQg(-1) fat, respectively, which were only about one fourth of the levels in Japan. In addition, no difference was found in the chemical levels except dl-PCBs between the urban and rural areas. Based on the results of an in-person interview of the Chinese mothers using a 59-item questionnaire, freshwater fish consumption was found to correlate with the body burden of dioxins. Principal component analysis of dioxin congeners revealed that the patterns of dioxins in the Hebei urban and rural areas are quite similar; however, they are clearly different from those in Japan. Collectively, our results suggest that the lower body burdens of dioxin in Hebei may be due in part to the relatively slow industrialization and a lower consumption of marine foods. Finally, the results indicate that comprehensive monitoring of dioxins and dl-PCBs in humans as well as in the environment and foods is necessary in China.

An abandoned gypsum mine has been discovered beneath the route of a highway construction in Hunan province, south China. Due to the highway construction and operations safety, there is an urgent need for a comprehensive stability analysis of the abandoned mining area. The 3D laser scanning detection technique has been adopted, and over 400 drillholes were strategically placed near the highway to capture the spatial information of the abandoned gypsum mine. The ore body has an average mining thickness of about 3 m, and the depth of the mining roof ranges from 40 to 60 m, with an average span of 16 m. Based on the research achievements in the engineering geological investigation, rock mass quality assessment, and geometry information, a simplified numerical model has been established for stability analysis. The numerical model employed the IMASS rock mass constitutive model to conduct a stability analysis of the abandoned gypsum mine during the excavation process and in the medium to long term. The IMASS constitutive model can effectively reflect the entire process of rock mass from microscopic damage to macroscopic instability, and the numerical simulation of current and long-term stages provides a much greater understanding of the mining room stability and the effect of various geo-mechanical parameters not considered in traditional empirical methods. The abandoned gypsum mine stability is guaranteed in the mining and current stages. However, the numerical results showed that a 0.4 m spalling thickness of the sidewalls can cause an overall instability and failure of the abandoned mine, and reinforcement measures must be taken for long-term safety. The stability of the abandoned gypsum mine with filling solutions was also evaluated numerically. [ABSTRACT FROM AUTHOR]

Based on the Xiabeishan No.2 tunnel project of the Hang-Shao-Tai high-speed railway in China, the mechanical behavior of the anchor bolts for shallow super-large-span (SSLS) tunnels in weak rock mass is comprehensively investigated through laboratory tests, numerical simulation, and field tests. Firstly, an eight-month field test is conducted in the Xiabeishan No.2 tunnel, and it is discovered that the blasting vibration created by the construction of the middle pilot tunnel caused serious damage to the temporary support, seriously affecting the development of the bolt axial force and causing great construction risks. Then, the refined finite difference model of the SSLS tunnels is formulated, and a series of field and laboratory tests are conducted to acquire the calculation parameters. By comparing the monitored and simulated bolt axial force, the reliability of the numerical model is verified. Subsequently, the influence of the rock condition, construction scheme and bolt length on the mechanical behavior of anchor bolts is discussed. It is revealed that the rock grade significantly affects the bearing characteristics of anchor bolts. The construction scheme can greatly affect the magnitude and development mode of the bolt axial force, but the final distribution characteristics of the bolt axial force do not change regardless of the construction sequence. The axial force of the anchor bolts grows rapidly with the bolt length when the bolt length is within 18 m; meanwhile, when the bolt length exceeds 18 m, increasing the bolt length has a limited effect on the improvement in the bolt support performance. Finally, some optimization measures are proposed according to the monitoring data and simulation results. [ABSTRACT FROM AUTHOR]

Background and objectives: In light of the growing burden of chronic kidney disease (CKD), it is of particular importance to create disease prediction models that can assist healthcare providers in identifying cases of CKD individual risk and integrate risk-based care for disease progress management. The objective of this study was to develop and validate a new pragmatic end-stage kidney disease (ESKD) risk prediction utilizing the Cox proportional hazards model (Cox) and machine learning (ML). Design, setting, participants, and measurements: The Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE), a multicenter CKD cohort in China, was employed as the model's training and testing datasets, with a split ratio of 7:3. A cohort from Peking University First Hospital (PKUFH cohort) served as the external validation dataset. The participants' laboratory tests in those cohorts were conducted at PKUFH. We included individuals with CKD stages 1~4 at baseline. The incidence of kidney replacement therapy (KRT) was defined as the outcome. We constructed the Peking University-CKD (PKU-CKD) risk prediction model employing the Cox and ML methods, which include extreme gradient boosting (XGBoost) and survival support vector machine (SSVM). These models discriminate metrics by applying Harrell's concordance index (Harrell's C-index) and Uno's concordance (Uno's C). The calibration performance was measured by the Brier score and plots. Results: Of the 3216 C-STRIDE and 342 PKUFH participants, 411 (12.8%) and 25 (7.3%) experienced KRT with mean follow-up periods of 4.45 and 3.37 years, respectively. The features included in the PKU-CKD model were age, gender, estimated glomerular filtration rate (eGFR), urinary albumin–creatinine ratio (UACR), albumin, hemoglobin, medical history of type 2 diabetes mellitus (T2DM), and hypertension. In the test dataset, the values of the Cox model for Harrell's C-index, Uno's C-index, and Brier score were 0.834, 0.833, and 0.065, respectively. The XGBoost algorithm values for these metrics were 0.826, 0.825, and 0.066, respectively. The SSVM model yielded values of 0.748, 0.747, and 0.070, respectively, for the above parameters. The comparative analysis revealed no significant difference between XGBoost and Cox, in terms of Harrell's C, Uno's C, and the Brier score (p = 0.186, 0.213, and 0.41, respectively) in the test dataset. The SSVM model was significantly inferior to the previous two models (p < 0.001), in terms of discrimination and calibration. The validation dataset showed that XGBoost was superior to Cox, regarding Harrell's C, Uno's C, and the Brier score (p = 0.003, 0.027, and 0.032, respectively), while Cox and SSVM were almost identical concerning these three parameters (p = 0.102, 0.092, and 0.048, respectively). Conclusions: We developed and validated a new ESKD risk prediction model for patients with CKD, employing commonly measured indicators in clinical practice, and its overall performance was satisfactory. The conventional Cox regression and certain ML models exhibited equal accuracy in predicting the course of CKD. [ABSTRACT FROM AUTHOR]

Granite residual soil is a common engineering material, and its mechanical properties are of great importance to engineering safety. This kind of soil presents obvious structural characteristics, and many researchers have emphasized the significance of its structural features. According to previous experiments, from a macroscopic perspective, many researchers have investigated the structural relationship between undisturbed and remolded soils, but few studies have considered it in the mesoscopic aspect. Adopting DEM (a mesomechanical simulation method), we can study how the structure affects the mechanical process between undisturbed and remolded soil. Therefore, this paper combines DEM with laboratory tests to study the structural characteristic correlation between undisturbed and remolded soil. The results indicate that a weak cohesion effect exists in undisturbed soil, and the damage of weak cohesion elements accompanies the failure process. Weak cohesion elements in undisturbed soil cause inhomogeneities in deformation, stress state, and damage accumulation, which ultimately causes differences in strength curves. This paper explains the mechanism of the structural effect on mechanical evolution from a mesomechanical perspective. The DEM simulation method proposed in this paper can be applied to structured soils and better guide engineering practice. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to develop and validate a multimorbidity index using self-reported chronic conditions for predicting 5-year mortality risk. Methods: We analyzed data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and included 11,853 community-dwelling older adults aged 65–84 years. Restrictive association rule mining (ARM) was used to identify disease combinations associated with mortality based on 13 chronic conditions. Data were randomly split into the training (N = 8,298) and validation (N = 3,555) sets. Two multimorbidity indices with individual diseases only (MI) and disease combinations (MIDC) were developed using hazard ratios (HR s) for 5-year morality in the training set. We compared the predictive performance in the validation set between the models using condition count, MI, and MIDC by the concordance (C) statistic, the Integrated Discrimination Improvement (IDI), and the Net Reclassification Index (NRI). Results: A total of 13 disease combinations were identified. Compared with condition count (C-statistic: 0.710), MIDC (C-statistic: 0.713) showed significantly better discriminative ability (C-statistic: p = 0.016; IDI: 0.005, p < 0.001; NRI: 0.038, p = 0.478). Compared with MI (C-statistic: 0.711), the C-statistic of the model using MIDC was significantly higher (p = 0.031), while the IDI was more than 0 but not statistically significant (IDI: 0.003, p = 0.090). Conclusion: Although current multimorbidity status is commonly defined by individual chronic conditions, this study found that the multimorbidity index incorporating disease combinations showed supreme performance in predicting mortality among community-dwelling older adults. These findings suggest a need to consider significant disease combinations when measuring multimorbidity in medical research and clinical practice. [ABSTRACT FROM AUTHOR]

Background: In China, the prevalence and mortality of colorectal cancer (CRC) have always been high, and more than 95% of CRC cases have evolved from colorectal polyps (CPs), especially adenoma. Early detection and treatment of CPs through colonoscopy is essential to reduce the incidence of CRC. Helicobacter pylori (Hp) is regarded as a risk factor for gastritis and gastric cancer and may also be a risk factor for CPs and CRC. However, few studies based on vast clinical cases exist in China to clarify whether Hp is a risk factor for CPs and CRC, and whether Hp-positive patients need to undergo colonoscopy checks earlier. This article attempts to make up for that deficiency. Method: This cross-sectional study was conducted based on 13,037 patients without a treatment history of Hp who underwent their first gastroscopy and colonoscopy simultaneously at The First Affiliated Hospital of Zhejiang Chinese Medical University from January 2018 to December 2019. Pearson χ2 test and logistic regression were used to determine whether Hp is a risk factor for CPs and CRC. Multifactor analysis of variance was used to define the impact of Hp on CPs prevalence with different ages, sexes. Results: For Chinese individuals, Hp is a risk factor for CPs and CRC. The odds ratio (OR) value are 1.228 (95% CI, 1.130 to 1.336) and 1.862 (95% CI 1.240-2.796), respectively. Hp-positive patients have a higher probability of multiple or large intestinal polyps. However, Hp infection does not increase the incidence of adenomas, nor does it affect the pathological type of adenomas. The OR of Hp on the risk of CPs was 1.432 (95%CI 1.275-1.608) for males but increased to 1.937 (95%CI 1.334-2.815) for those aged 35 to 40. For females, the results were similar. Conclusions: For the Chinese, Hp is a risk factor for CPs and CRC (OR>1); the infection of Hp increased CPs risk in Chinese of all ages, especially aged 35-40, suggesting that Hp-positive patients should undergo colonoscopy frequently. [ABSTRACT FROM AUTHOR]

Turtle eggs containing embryos are exceedingly rare in the fossil record. Here, we provide the first description and taxonomic identification, to our knowledge, of a fossilized embryonic turtle preserved in an egg, a fossil recovered from the Upper Cretaceous Xiaguan Formation of Henan Province, China. The specimen is attributed to the Nanhsiungchelyidae (Pan-Trionychia), an extinct group of large terrestrial turtles (possibly the species Yuchelys nanyangensis). The egg is rigid, spherical, and is one of the largest and thickest shelled Mesozoic turtle eggs known. Importantly, this specimen allowed identification of other nanhsiungchelyid egg clutches and comparison to those of Adocidae, as Nanhsiungchelyidae and Adocidae form the basal extinct clade Adocusia of the Pan-Trionychia (includes living soft-shelled turtles). Despite the differences in habitat adaptations, nanhsiungchelyids (terrestrial) and adocids (aquatic) shared several reproductive traits, including relatively thick eggshells, medium size clutches and relatively large eggs, which may be primitive for trionychoids (including Adocusia and Carrettochelyidae). The unusually thick calcareous eggshell of nanhsiungchelyids compared to those of all other turtles (including adocids) may be related to a nesting style adaptation to an extremely harsh environment. [ABSTRACT FROM AUTHOR]

In caving mining, the successful initiation and propagation of caving require one low-dip joint set. However, not every mine has a low-dip joint set. The Hemushan Iron Mine in China was taken as the engineering background, and the caving characteristics of rock mass with inclined joints were analyzed based on the synthetic rock mass (SRM) model. First, the inclined joints were investigated in the Hemushan Iron Mine. Second, model parameters were determined based on the geological conditions of the mine, and seven models were established. Third, the caving process was simulated, and caving characteristics were monitored. For rock mass with inclined joints after undercutting, the research showed that the crack zone was significant, and the crack zone existed not only around the undercut area but also further away in the model. The stress concentration areas dispersed in the model except for the top of the undercut area. The caving line was not a standard arch, and the highest point of the caving line was biased towards the direction of the undercut. Under the same undercut width, with the decrease of joint length in the joint system, the number of cracks decreased, the degree of stress concentration became weaker, and the height of the caving line decreased. [ABSTRACT FROM AUTHOR]

The occurrence of rockburst is related to the surrounding rock stress and geological rock mass strength. Rockburst occurs frequently during the construction at a deep tunnel in southwest China (a tunnel with a depth of approximately 2080 m, and a length of 13 km), leading to casualties, damage to construction equipment, and schedule delays. The application of the rockburst criteria based on the stress-strength/strength-stress ratio shows that they are not suitable for the construction stage. This paper suggests a simple and feasible rockburst intensity criterion based on the Geological Strength Index (GSI) for the construction stage. In this criterion, the strength of the rock mass exposed during excavation is estimated by the Hoek-Brown criterion and is used to reflect the geological conditions of the surrounding rock, considering the influences of the joint conditions and engineering disturbance. The maximum principal stress along the tunnel is obtained by the in situ stress inversion. The ratio of the rock mass strength to the maximum principal stress (σcm/σ1) is taken as the evaluation index. The criterion is as follows: σcm/σ1 > 1.2, none rockburst; 0.75 < σcm/σ1 ≤ 1.2, slight rockburst; 0.4 < σcm/σ1 ≤ 0.75, moderate rockburst; and σcm/σ1 ≤ 0.4, intense rockburst. The engineering applications show the reliability of this rockburst intensity criterion. The results of this paper provide a reference for rockburst intensity evaluation during the construction stage of deep tunnels. [ABSTRACT FROM AUTHOR]

Geological strength index GSI , disturbance factor (D), material constant m i , and uniaxial compressive strength σ ci of the intact rock are essential input parameters IPs of the Hoek–Brown H − B criterion. Mechanical parameters MPs of the engineering rock mass, including elastic modulus E , cohesion c , and internal friction angle φ estimated by the H–B criterion, and the predicted excavation response of surrounding rock, including the displacement and excavation damage zone EDZ based on the MPs, are of high relevance with the four IPs of the H–B criterion. In this paper, the deep and huge underground cavern excavated in basalt from a hydropower station under construction in the southwest of China is used to analyse the sensitivity of the IPs on the MPs, the displacement, and EDZ of the surrounding rock mass. Firstly, the H–B criterion is applied to estimate the MPs, among which the IPs are obtained from a series of in situ and laboratory tests, including borehole camera observation, wave velocity test, uniaxial and triaxial compression tests, and so on. Secondly, the sensitivity relationships between IPs, MPs, and prediction results of displacement and EDZ are established and described quantitatively by the sensitivity factor (si). Results show that the MPs of the rock mass are more sensitive to GSI and D ⋅ GSI and σ ci are high-sensitivity parameters affecting the displacement and EDZ. Finally, the variations in the estimated MPs and associated prediction results concerning excavation response, which are caused by the uncertainties in the determination of the IPs, are further quantified. This study provides a straightforward assessment for the variability of the rock mass parameters estimated by the H–B criterion. It also gives a valuable reference to similar geotechnical engineering for the determination of rock mass parameters in the preliminary design. [ABSTRACT FROM AUTHOR]

The Geological Strength Index (GSI) is an important parameter for estimating rock mass properties and can be estimated either through direct observations or by using a quantitative GSI chart or equations. This study aims to discuss the applicability of the RMR89 method and the latest version of GSI|2013 by applying them to a case study and to the data published in the earlier papers. The relevant rock mass properties, including blockiness and discontinuity conditions, of the walls of 15 exploratory adits with a total length longer than 1100 m in a hydropower project in China have been assessed to provide data for the analysis. In addition, a repeat analysis of the earlier published data has been conducted to validate the results derived from the case study. The results show that the GSI values calculated with the RMR89 are generally larger than those obtained from the qualitative GSI chart, with an average magnitude of about five. The GSI values predicted from the values of JCond89 and RQD are consistent with those derived through the qualitative observational method for a medium-quality rock mass but are relatively smaller or larger for a poor-quality (i.e., GSI<45) or a high-quality (i.e. GSI>65) rock mass, respectively. By comparing the results of the RMR89 method and the qualitative GSI chart method and analyzing the classification factors considered by the two methods, two new equations based on the RMR89 system have been developed for estimating the GSI. Their application to the case study and the published data prove that these two equations have higher predictive accuracy than the original RMR89 method and the latest version of GSI|2013. It is expected that the acquisition of more engineering examples will enable the two formulas to be further verified and improved. [ABSTRACT FROM AUTHOR]

Acquired brain ischemia-and reperfusion-injury (IRI), including both Ischemic stroke (IS) and Traumatic Brain injury (TBI), is one of the most common causes of disability and death in adults and represents a major burden in both western and developing countries worldwide. China's clinical neurological therapeutic experience in the use of traditional Chinese medicines (TCMs), including TCM-derived active compounds, Chinese herbs, TCM formulations and decoction, in brain IRI diseases indicated a trend of significant improvement in patients' neurological deficits, calling for blind, placebo-controlled and randomized clinical trials with careful meta-analysis evaluation. There are many TCMs in use for brain IRI therapy in China with significant therapeutic effects in preclinical studies using different brain IRI-animal. The basic hypothesis in this field claims that in order to avoid the toxicity and side effects of the complex TCM formulas, individual isolated and identified compounds that exhibited neuroprotective properties could be used as lead compounds for the development of novel drugs. China's efforts in promoting TCMs have contributed to an explosive growth of the preclinical research dedicated to the isolation and identification of TCM-derived neuroprotective lead compounds. Tanshinone , is a typical example of TCM-derived lead compounds conferring neuroprotection toward IRI in animals with brain middle cerebral artery occlusion (MCAO) or TBI models. Recent reports show the significance of the inflammatory response accompanying brain IRI. This response appears to contribute to both primary and secondary ischemic pathology, and therefore anti-inflammatory strategies have become popular by targeting pro-inflammatory and anti-inflammatory cytokines, other inflammatory mediators, reactive oxygen species, nitric oxide, and several transcriptional factors. Here, we review recent selected studies and discuss further considerations for critical reevaluation of the neuroprotection hypothesis of TCMs in IRI therapy. Moreover, we will emphasize several TCM's mechanisms of action and attempt to address the most promising compounds and the obstacles to be overcome before they will enter the clinic for IRI therapy. We hope that this review will further help in investigations of neuroprotective effects of novel molecular entities isolated from Chinese herbal medicines and will stimulate performance of clinical trials of Chinese herbal medicine-derived drugs in IRI patients. [ABSTRACT FROM AUTHOR]

Background: The relationship between obstructive lung function and impaired renal function is unclear. This study investigated the dose-response relationship between obstructive lung function and impaired renal function.Methods: Two independent cross-sectional studies with representative sampling were applied. 1454 adults from rural Victoria, Australia (1298 with normal renal function, 156 with impaired renal function) and 5824 adults from Nanjing, China (4313 with normal renal function, 1511 with impaired renal function). Pulmonary function measurements included forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Estimated glomerular filtration rate (eGFR), and impaired renal function marked by eGFR <60 mL/min/1.73m2 were used as outcome.Results: eGFR increased linearly with FEV1 in Chinese participants and with FVC in Australians. A non-linear relationship with peaked eGFR was found for FEV1 at 2.65 L among Australians and for FVC at 2.78 L among Chinese participants, respectively. A non-linear relationship with peaked eGFR was found for the predicted percentage value of forced expiratory volume in 1 s (PFEV1) at 81-82% and for the predicted percentage value of forced vital capacity (PFVC) at 83-84% among both Chinese and Australian participants, respectively. The non-linear dose-response relationships between lung capacity measurements (both for FEV1 and FVC) and risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 3.05 L both for FEV1 and FVC, respectively. The non-linear relationship between PFEV and PVC and the risk of impaired renal function were consistently identified in both Chinese and Australian participants. An increased risk of impaired renal function was found below 76-77% for PFEV1 and 79-80% for PFVC, respectively.Conclusions: In both Australian and Chinese populations, the risk of impaired renal function increased both with FEV1 and FVC below 3.05 L, with PFEV1 below 76-77% or with PFVC below 79-80%, respectively. Obstructive lung function was associated with increased risk of reduced renal function. The screen for impaired renal function in patients with obstructive lung disease might be useful to ensure there was no impaired renal function before the commencement of potentially nephrotoxic medication where indicated (eg diuretics). [ABSTRACT FROM AUTHOR]

The temporal change patterns of laboratory data may provide insightful clues into the whole course of COVID-19. This study aimed to evaluate longitudinal change patterns of key laboratory tests in patients with COVID-19, and identify independent prognostic factors by examining the associations between laboratory findings and outcomes of patients. This multicenter study included 56 patients with COVID-19 treated in Jilin Province, China, from January 21, 2020 to March 5, 2020. The laboratory findings, epidemiological characteristics and demographic data were extracted from electronic medical records. The average value of eosinophils and carbon dioxide combining power continued to significantly increase, while the average value of cardiac troponin I and mean platelet volume decreased throughout the course of the disease. The average value of lymphocytes approached the lower limit of the reference interval for the first 5 days and then rose slowly thereafter. The average value of thrombocytocrit peaked on day 7 and slowly declined thereafter. The average value of mean corpuscular volume and serum sodium showed an upward trend from day 8 and day 15, respectively. Age, sex, lactate dehydrogenase, platelet count and globulin level were included in the final model to predict the probability of recovery. The above parameters were verified in 24 patients with COVID-19 in another area of Jilin Province. The risk stratification and management of patients with COVID-19 could be improved according to the temporal trajectories of laboratory tests.

Background: the impact of estimated glomerular filtration rate (eGFR) on stroke clinical outcomes remains controversial. We examined the association between eGFR and all-cause mortality, recurrent stroke, and stroke disability in patients with acute ischaemic stroke.Methods: we analysed 8865 patients with acute ischaemic stroke in the China National Stroke Registry (CNSR) between September 2007 and August 2008. Multivariate logistic regression analysis was used to evaluate the association between eGFR and 1-year all-cause mortality, recurrent stroke, and stroke disability. Low eGFR was defined as <45 ml/min/1.73 m2.Results: of 8865 acute ischaemic stroke patients included in the analysis, eGFR of <45 ml/min/1.73 m2 occurred in 394 (4.4%), eGFR of 45–59 ml/min/1.73 m2 in 675 (7.6%), eGFR of 60–89 ml/min/1.73 m2 in 3533 (39.9%), and eGFR of ≥90 ml/min/1.73 m2 in 4263 (48.1%) at baseline. Patients with reduced renal function were more likely to die, experience recurrent stroke or have stroke disability than patients with preserved renal function. After adjusting for both demographic and clinical risk factors, an eGFR of <45 ml/min/1.73 m2 was independently associated with 1-year all-cause mortality (OR: 2.65; 95% CI: 1.95–3.59) and recurrent stroke (OR: 1.97; 95% CI: 1.51–2.56) but not for stroke disability defined as modified Rankin Score of 2–6 (OR: 1.26; 95% CI: 0.95–1.67). These results were consistent in stratified analyses by age, diabetes or hypertension.Conclusions: a low eGFR was associated with increased risks of all-cause mortality and recurrent stroke independent of the traditional vascular risk factors in Chinese stroke patients. [ABSTRACT FROM AUTHOR]

The importance of in-situ rock block characterization has been realized for decades in rock mechanics and engineering, yet how to reliably measure and characterize the geometrical properties of blocks in varied forms of exposures and patterns of jointing is still a challenging task. Using a point cloud model (PCM) of rock exposures generated from remote sensing techniques, we developed a consistent and comprehensive method for rock block characterization that is composed of two different procedures and a block indicator system. A semi-automatic procedure towards the robust extraction of in-situ rock blocks created by the deterministic discontinuity network on rock exposures (PCM-DDN) was developed. A 3D stochastic discrete fracture network (DFN) simulation (PCM-SDS) procedure was built based on the statistically valid representation of the discontinuity network geometry. A multi-dimensional block indicator system, i.e., the block size, shape, orientation, and spatial distribution pattern for systematic and objective block characterization, was then established. The developed method was applied to a synthetic model of cardboard boxes and three different rock engineering scenarios, including a road cut slope from Spain and two open-pit mining slopes from China. Compared with existing empirical methods, the proposed procedures and the block indicator system are dependable and practically feasible, which can help enhance our understanding of block geometry characteristics in related applications. [ABSTRACT FROM AUTHOR]

BRCA1 is a tumor suppressor that has been found to be involved DNA synthesis during cell replication. In a recent study, the single nucleotide polymorphism (SNP), rs799917, in BRCA1 was found to be associated with the development and progression of various types of tumor. In the present study, the association between rs799917 and susceptibility to lung cancer was evaluated in a Han Chinese population in the Liaoning Province of China. The BRCA1 rs799917 genotypes (C/C, C/T and T/T) were analyzed using TaqMan quantitative PCR in 682 patients with lung cancer and 694 healthy controls, and the results were analyzed using a Student's t-test, a χ2 test and logistic regression analysis. Individuals carrying the C/T or T/T genotype had a lower risk of lung cancer compared with those carrying the C/C genotype [odds ratio (OR), 0.741; P=0.021; and OR, 0.610; P=0.011, respectively). The C/T + T/T genotype group had an even lower risk (OR, 0.709; P=0.005) compared with that in the C/C genotype group. In the stratified analyses of non-smokers, individuals with the C/T or T/T genotype had a lower risk of developing lung cancer compared with that in those carrying the C/C genotype (OR, 0.681; P=0.013; and OR, 0.569; P=0.021, respectively). The stratified analyses of the BRCA1 rs799917 polymorphism based on pathological type, chemotherapy and radiotherapy, showed that in the squamous cell carcinoma, non-chemotherapy and non-radiotherapy subgroups, individuals with the T/T genotype had a lower risk of lung cancer compared with that in those carrying the C/C genotype (OR, 0.454; P=0.007; OR, 0.485; P=0.002; and OR, 0.599; P=0.020, respectively). In conclusion, the T allele of the rs799917 SNP in BRCA1 was associated with a lower risk of lung cancer in the ethnic Han Chinese population in Liaoning Province and may represent a protective factor against lung cancer. [ABSTRACT FROM AUTHOR]