Grounded source transient electromagnetic 3D forward modeling with the spectral-element method and its application in hydraulic fracturing monitoring

A long wire with large current source transient electromagnetic (TEM) monitoring, with a large detection depth, low cost, safety, and environmental protection, has unique advantages in the testing and identification of unconventional reservoir fluid and the evaluation of stimulated reservoir volume. So, the TEM 3D forward modeling method has become a research hotspot. Although the finite-element method (FEM) is a type of numerical algorithm that has been widely applied in three-dimensional (3D) electromagnetic field forward modeling, the efficiency and accuracy of FEM require further improvement in order to meet the demand of fast 3D inversion. By increasing the order of the basis function and adjusting the principle of mesh discretization, the precision of the mixed-order spectral-element (SEM) result will be increased. The backward Euler scheme is an unconditionally stable technique which can ignore the impact of the scale of the time step. To achieve a better description of the nonlinear electromagnetic (EM) response of the grounded source TEM method and to optimize the efficiency and accuracy/precision of the 3D TEM forward modeling method significantly, we proposed the use of 3D TEM forward modeling based on the mixed-order SEM and the backward Euler scheme, which can obtain more accurate EM results with fewer degrees of freedom. To check its accuracy and efficiency, the 1D and 3D layered models are applied to compare the SEM results with the semi-analytical and FEM solutions. In addition, we analyzed the accuracy and efficiency of the SEM method for different types of order basis functions. Finally, we calculated the long-wire source TEM response for a practical 3D earth model of a shale gas reservoir for fracturing monitoring and tested the feasibility of the TEM method in a hydraulic fracturing monitoring area to further demonstrate the flexibility of the SEM method

Sex differences in the prevalence and clinical correlates of hyperhomocysteinemia in patients with bipolar disorder

Objective Sex differences in bipolar disorder are well recognized but little attention has been paid to sex differences in homocysteine or hyperhomocysteinemia in bipolar patients. This study compared gender differences in homocysteine levels and rates of hyperhomocysteinemia in Chinese inpatients with bipolar disorder. Methods A total of 198 BD patients and 84 healthy controls were enrolled. The Young Mania Rating Scale, Hamilton Depression Rating Scale, and the Clinical Global Impressions-Severity scale were used to assess the affective symptomatology. Fasting plasma Hcy levels were measured by high-performance liquid chromatography. Results Men had higher homocysteine levels than women and the prevalence of hyperhomocysteinemia in male patients was approximately twice that in female patients. Logistic regression analyses showed that HHcy was associated with less frequent use of valproate in males and being overweight in females. Further correlation analysis and multivariate regression analysis demonstrated that Hcy levels were inversely correlated with valproate treatment in men and positively associated with overweight in women. Conclusions In bipolar patients, there are significant differences between sexes in the levels of homocysteine and prevalence of hyperhomocysteinemia. This appears to be associated with lower prevalence of valproate prescribing in men and with being overweight in women.</p

Diabetes in late-life schizophrenia: Prevalence, factors, and association with clinical symptoms

Objective: The prevalence of diabetes mellitus has been found to be higher in patients with schizophrenia. Older patients are the fastest-growing segment of the schizophrenia population. However, few studies have explored diabetes in older patients with schizophrenia. Therefore, this study aimed to determine the prevalence and characteristics of factors associated with diabetes in Chinese patients with late-life schizophrenia (LLS), which has not been reported in previous studies. Methods: A total of 289 inpatients aged 60 or above who met the DSM-IV criteria for schizophrenia were recruited. The severity of psychopathology was assessed by the Positive and Negative Syndrome Scale (PANSS). Diabetes was diagnosed by fasting blood glucose tests, or oral glucose tolerance tests. Results: The overall prevalence of diabetes in LLS patients was 25.3%. The prevalence of diabetes in female patients was significantly higher than that in male patients (35% vs. 21.53%). Other factors associated with diabetes included higher BMI, greater waistline (only for males), higher levels of triglyceride, and more severe positive symptoms. Conclusion: These results indicate that the prevalence of diabetes in LLS patients is similar to that in the age matched general population. Female gender, excess weight and abdominal obesity, dyslipidemia, and clinical symptoms can be potential risk factors of diabetes in the LLS patient group

Association of thyroid dysfunction with suicide attempts in first-episode and drug naive patients with major depressive disorder

Backgrounds: Thyroid dysfunction was reported to be associated with depression; however, its role in suicide risk in patients with major depressive disorder (MDD) remains unclear. The objective of this study was to compare thyroid function between suicide attempters and non-suicide attempters in a large sample of first episode drug naive (FEDN) MDD patients, which received little systemic investigation. Methods: A total of 1718 outpatients with diagnosis of MDD at their first episode were recruited. Their sociodemographic, clinical data and thyroid function parameters were collected. The positive subscale of the Positive and Negative Syndrome Scale (PANSS), Hamilton Anxiety Rating Scale (HAMA) and Hamilton Depression Rating Scale (HAMD) were measured for psychotic, anxiety and depressive symptoms, respectively. Results: Our results showed that compared with non-suicide attempters, suicide attempters had greater scores on HAMD, HAMA and PANSS psychotic symptoms and higher serum levels in thyroid stimulating hormone (TSH), anti-thyroglobulin (TgAb) and thyroid peroxidases antibody (TPOAb) (all p < 0.001). Further logistic regression analysis indicated that suicide attempts were associated with severe anxiety with an adjusted odds ratio (OR) of 2.704 and TPOAb with an adjusted OR of 2.188. Limitations: No causal relationship could be drawn due to the cross-sectional design. Conclusions: Our results indicate TSH, TgAb and TPOAb may be promising biomarkers of suicide risk in MDD, suggesting the importance of regular assessment of thyroid function parameters for suicide prevention, and possible treatment for impaired thyroid function for intervention of suicide in MDD patients

Obesity, altered oxidative stress, and clinical correlates in chronic schizophrenia patients

Abstract Antipsychotic pharmacotherapy is strongly obesogenic and is associated with increased oxidative stress in patients with schizophrenia. However, whether these changes reflect psychopathology, antipsychotic efficacy, or some other factor is not known. Our study aims to investigate the degree of oxidative stress in different BMI categories and to identify clinical symptomatology that may be paired with increased oxidative stress in a schizophrenia population. To this end, we performed a cross-sectional study and recruited 89 long-term inpatients with schizophrenia and collected the following variables: plasma malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), routine biochemical analysis, and psychopathology through the Positive and Negative Syndrome Scale (PANSS). The results indicate that the levels of the lipid peroxidation product, MDA, were significantly higher in the high BMI group than the low (normal) BMI group. As expected, high BMI was associated with an atherogenic lipid profile; however, it was also associated with fewer psychopathological symptoms. Multiple regression analysis found that MDA levels, the PANSS general psychopathology subscore, and triglyceride levels (all p < 0.05) were independent contributors to the BMI in patients. These results suggested that oxidative stress may play an important role in antipsychotic-induced weight gain. Further investigations using the longitudinal design in first-episode schizophrenia patients are needed to explore the beneficial effect of antioxidants on the abnormal lipid metabolism mediated by antipsychotic treatment

Prevalence and Clinical Correlates of and Cognitive Function at the Time of Suicide Attempts in First-Episode and Drug-Naive Patients With Schizophrenia

Background: It is well established that patients with chronic schizophrenia have a substantially higher rate of attempted and completed suicide than the general population. However, the actual prevalence of suicide attempts at first-episode psychosis is relatively unknown. Previous studies showed that suicidal schizophrenia patients demonstrate higher cognitive function than nonsuicidal patients, though with inconsistent results. The aims of the study were to examine the prevalence of suicide attempts and the association of this prevalence with demographic and clinical variables and cognitive function in Chinese first-episode, drug-naive (FEDN) schizophrenia patients using a cross-sectional and case-control design. Method: A total of 357 FEDN inpatients meeting DSM-IV criteria for schizophrenia and 380 healthy controls were enrolled and completed a detailed in-house questionnaire. The suicide attempt data were collected from medical records and interviews with the patients and their family members. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was administered to measure cognition in the 28 patients with and 95 patients without a history of suicide attempt and 151 healthy controls. Also, patients were rated on the Positive and Negative Syndrome Scale (PANSS). This study was conducted from June 2013 to December 2015. Results: A suicide attempt rate of 12.0% was found in inpatients with first-episode schizophrenia. The attempters were more likely to smoke (34.4% vs 17.9%; chi(2) = 5.49, P =.019) and had lower severity of negative symptoms (F-1,F-354 = 4.12, P =.043) as compared to FEDN patients without a suicide attempt. All 5 RBANS subscales (all P .05) showed significantly lower cognitive performance for FEDN patients than for healthy controls. Among the FEDN patients, the suicide attempters performed better than nonattempters on attention (F-1,F-121 = 5.12, P =.025), with an effect size of 0.49. The following variables were independently associated with suicide attempt as shown by multivariate regression analysis: PANSS negative symptom subscale score (Wald chi(2)(1) = 7.90 P =.005; adjusted OR = 0.807, 95% CI, 0.696-0.936) and Attention (Wald chi(2)(1) = 4.69, P =.03; adjusted OR = 0.957, 95% CI, 0.918-0.997). Conclusions: FEDN patients with schizophrenia attempt suicide more often than the general population. The suicidal patients were more likely to smoke, had lower severity of negative symptoms, and showed better attention than nonsuicidal patients