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Traumatic axonal injury (TAI) may result in the disruption of brain functional networks and is strongly associated with cognitive impairment. However, the neural mechanisms affecting the neurocognitive function after TAI remain to be elucidated. We collected the resting-state functional magnetic resonance imaging data from 28 patients with TAI and 28 matched healthy controls. An automated anatomical labeling atlas was used to construct a functional brain connectome. We utilized a graph theoretical approach to investigate the alterations in global and regional network topologies, and network-based statistics analysis was utilized to localize the connected networks more precisely. The current study revealed that patients with TAI and healthy controls both showed a typical small-world topology of the functional brain networks. However, patients with TAI exhibited a significantly lower local efficiency compared to healthy controls, whereas no significant difference emerged in other small-world properties (Cp, Lp, γ, λ, and σ) and global efficiency. Moreover, patients with TAI exhibited aberrant nodal centralities in some regions, including the frontal lobes, parietal lobes, caudate nucleus, and cerebellum bilaterally, and right olfactory cortex. The network-based statistics results showed alterations in the long-distance functional connections in the subnetwork in patients with TAI, involving these brain regions with significantly altered nodal centralities. These alterations suggest that brain networks of individuals with TAI present aberrant topological attributes that are associated with cognitive impairment, which could be potential biomarkers for predicting cognitive dysfunction and help understanding the neuropathological mechanisms in patients with TAI.

To evaluate the predictive value of sequential organ failure assessment (SOFA) for 28-day mortality in patients with post-cardiac arrest syndrome (PCAS).Retrospective analysis of 125 patients with PCAS who were treated in Emergency Intensive Care Unit (EICU) of Wenzhou People's Hospital from July 2016 to July 2021. Clinical data were collected, including age, gender, underlying diseases, acute physiology and chronic health evaluation II (APACHE II), SOFA score on admission to EICU and 28-day mortality. Univariate and multivariate Logistic regression model was constructed to analyze the influencing factors of PCAS patients, which was used to examine the independent correlation between SOFA score and 28-day mortality. Receiver operator characteristic curve (ROC curve) was used to determine the best predictive value of SOFA score and 28-day mortality in PCAS patients.Among the 125 PCAS patients, there were 91 males and 34 females with an average age of (58.7±15.1) years old, and 97 died and 28 survived within 28 days. The overall SOFA score ranged from 7 to 15 points, with an average of 10.9 (10.0, 12.0) points. The SOFA score of non-survival group was significantly higher than that of the survival group [points: 11.0 (10.0, 12.0) vs. 9.5 (9.0, 10.0), P0.05]. This difference between SOFA score mainly caused by the neurological and cardiovascular systems. After excluding neurological factors, the SOFA score of the non-survival group was still significantly higher than that of the survival group [points: 8.0 (6.0, 8.0) vs. 6.5 (6.0, 7.0), P0.05]. SOFA score was found to be an independent risk factor for 28-day mortality in PCAS patients by multifactorial Logistic regression analysis [odds ratio (OR) = 1.97, 95% confidence interval (95%CI) was 1.24-3.04]. The correlation between neurological score and mortality was the highest in subgroups (OR = 3.47, 95%CI was 1.04-11.52). The area under the ROC curve (AUC) predicted by SOFA score was 0.81 (95%CI was 0.73-0.89). When SOFA score cut-off value was 10.5 points (10 or 11 points), the sensitivity and specificity of SOFA score for predicting 28-day mortality in patients with PCAS were 67.0% and 82.1%, respectively.The SOFA score is quite accurate in predicting 28-day mortality in patients with PCAS.

Serum lactate dehydrogenase (LDH) has been identified as an independent risk factor for predicting all-cause mortality in patients with multiple diseases. However, the prognostic value of LDH levels in post-cardiac arrest patients remains uncertain. This study aimed to assess the association between LDH and mortality in intensive care unit (ICU) patients after cardiac arrest. This retrospective observational study is based on data from the Dryad Digital Repository, which included 374 consecutive adult patients after cardiac arrest. Patients were divided into 2 groups based on median LDH values. A multivariate Cox proportional hazards model was established to assess the independent relationship between LDH and ICU mortality. Cumulative mortality was compared using Kaplan-Meier curves. The cohort included 374 patients, of which 51.9% (194/374) died in the ICU. The overall death rate from cardiac arrest was significantly higher for patients with LDH ≥ 335 IU/L (59.6%) than for those with LDH 335 IU/L (44.1%). In multiple Cox regression models, hazard ratios (HR) and corresponding 95% confidence intervals (CI) for logLDH and the 2 LDH groups were 1.72 (1.07, 2.78) and 1.42 (1.04, 1.93), respectively. Participants with LDH ≥ 335IU/L had a higher incidence of ICU mortality than LDH 335 IU/L, as shown by the Kaplan-Meier curves (P = .0085). Subgroup analysis revealed that the association between LDH and ICU mortality was vitally stable, with all P interactions from different subgroups .05. Serum LDH levels are positively associated with ICU mortality in patients after cardiac arrest, especially for patients with LDH ≥ 335 IU/L.

(1) Background: River health assessment provides the foundation for sustainable river development and management. However, existing assessments have no uniform standards and methods. (2) Methods: The combination weighting method was proposed, drawing on the advantages of subjective and objective weighting methods. To comprehensively investigate the river health level, an index system based on 16 indices selected from river morphology, river water environment, riparian condition, and social services level was established. The method and framework were applied to the Beijing section of Yongding River in China. (3) Results: The comprehensive weights of river morphology, river water environment, riparian condition, and social services are 0.1614, 0.3170, 0.4459, and 0.0757, respectively. The river health comprehensive index of Yongding River is 3.805; the percentages of excellent, healthy, sub-healthy, unhealthy, and sick river segments are 0%, 11%, 69%, 20%, and 0%, respectively. (4) Conclusions: The results indicate that Yongding River is in a sub-healthy state, and the riparian condition is the key factor that affects the river ecosystem health. Health level exhibited a remarkable spatial variation, mainly influenced by anthropogenic activities, and effective measures are needed to minimize the impact in fragile ecological areas.

Altered cerebral structure and function have been observed in young survivors of acute lymphoblastic leukemia (ALL). However, the topological organization of the morphological brain networks (MBNs) has not yet been investigated at the individual level. Twenty-three young survivors of ALL and twenty healthy controls (HCs) were recruited and underwent T1-weighted magnetic resonance imaging (MRI) scanning. After preprocessing and segmentation, individual-based MBNs were constructed based on the morphological similarity of gray matter using the combined Euclidean distance. Young survivors showed a significantly lower global clustering coefficient (p = 0.008) and local efficiency (p = 0.035) compared with HCs. In addition, ALL survivors exhibited bidirectional alterations (decreases and increases) in nodal centrality and efficiency around the Rolandic operculum and posterior occipital lobe (p < 0.05, false discovery rate (FDR) corrected). Altered nodal topological efficiencies were associated with off-therapy duration and verbal memory capacity in the digit span test (p < 0.05, FDR corrected). Network-based statistical analysis revealed decreased morphological connections mainly in the pallidum subnetwork, which was negatively correlated with off-therapy durations (p < 0.05). Overall, the topological organization of the individual-based MBNs was disrupted in the young survivors of ALL, which may play a crucial role in executive efficiency deficits.

Objective Using functional connectivity density (FCD) mapping measured by resting-state functional magnetic resonance imaging (rs-fMRI), an ultrafast data-driven graph theory approach, we attempted to study the abnormalities in neural activity of young survivors of acute lymphoblastic leukemia (ALL) and to explore the neuropathological evidence of chemotherapy-related cognitive impairment of patients. Methods Twenty young survivors of ALL and 18 well-matched healthy controls (HCs) were recruited in this study. All ALL patients and healthy controls underwent rs-fMRI scans and completed neurocognitive testing. The between-group differences in short-range and long-range FCD were calculated by the option of degree centrality (DC) in MATLAB software after preprocessing. The correlations between the FCD value and each of the neurocognitive outcomes were analyzed in the ALL patients. Results The group-averaged FCD maps showed similar spatial patterns between the two groups. Compared with the HCs, ALL patients showed decreased long-range FCD in regions of the bilateral lingual gyrus, cingulate cortex, hippocampal gyrus, and right calcarine fissure. Simultaneously, decreased regions in the short-range FCD map were the bilateral lingual gyrus, cingulate cortex, parahippocampal gyrus and right calcarine fissure. Increased functional connectivity (FC) was observed between the region with decreased long-range FCD and the posterior cerebellar lobe, and decreased FC was observed between the region and the middle occipital gyrus, cuneus and lingual gyrus. Thus, there existed no brain areas with increased FCD. The decreased short-range FCD value of ALL patients was positively correlated with the score on the Digit Span Test (Forward), and the increased FC value was negatively correlated with the score on the Trail Making Test part A. Conclusion Our results suggest the altered functional connectivity of young survivors of ALL in the posterior region of the brain and posterior lobe of the cerebellum. Alterations in spontaneous neuronal activity seem to parallel the neurocognitive testing, which indicates that the rs-fMRI could be used as a neuroimaging marker for neurological impairment in ALL patients.

The efficacy of whole-body vibration for functional improvement in stroke patients remains controversial. We conduct a systematic review and meta-analysis to explore the influence of whole-body vibration on functional improvement in stroke patients.We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through June 2018 for randomized controlled trials (RCTs) assessing the effect of whole-body vibration on functional improvement in stroke patients. This meta-analysis is performed using the random-effect model.Eight RCTs are included in the meta-analysis. Overall, compared with control group for stroke patients, whole-body vibration has no positive impact on 6 min walk test (6MWT) distance (standard mean difference (Std. MD)=−0.28; 95% confidence interval (CI)=−0.66 to 0.11; P=0.16), timed-up-and-go (TUG) test (Std. MD=0.15; 95% CI=−0.54 to 0.84; P=0.67), Fugl-Meyer assessment (Std. MD=0.33; 95% CI=−0.23 to 0.89; P=0.25), Berg Balance Scale (Std. MD=0.19; 95% CI=−0.43 to 0.80; P=0.55), and activities specific balance (ABC) scale (Std. MD=−0.22; 95% CI=−0.62 to 0.17; P=0.26).Whole-body vibration shows no notable influence on 6MWT distance, TUG test, Fugl-Meyer assessment, Berg Balance Scale, and ABC scale in stroke patients.

Background:Ginsenoside Rg1 (Rg1) is the main active compound of ginseng herbs.Objective:The aim of this study is to develop a rapid, selective and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine the levels of Rg1 in rat plasma and investigate the pharmacokinetics and bioavailability of Rg1 in rats.Methods:Chromatographic separation was achieved on an UHPLC-MS/MS system with an UPLC BEH C18 column using an elution gradient of a mixture of acetonitrile and water (with 0.1% formic acid). The analytes were quantitatively determined by negative-mode electrospray tandem MS.Results:The linearity of the calibration curve was from 2 to 1,000 ng/mL (r ≥ 0.9956), and the lower limit of quantification was 2 ng/mL. The inter-day and intra-day precision were both lower than 12.0%, and the accuracy ranged from 90.6 to 109.7%. The recovery of the targets was higher than 87.0%, and the matrix effect at three different analyte concentrations were from 89.0 to 97.2%. The bioavailability of Rg1 was only 6.1% due to a poor oral absorption.Conclusion:This new quantitative method was found to be sensitive, rapid and selective, and was successfully used to study the pharmacokinetics of Rg1 after intravenous and oral administration in rats.

BACKGROUND: Primary angle-closure glaucoma (PACG) is a neurodegenerative disease. Previous structural and functional studies of functional magnetic resonance imaging (fMRI) have demonstrated widespread dysfunction of spontaneous activity in the PACG brain. In this study, we applied a data-driven graph theory approach of functional connectivity density (FCD) mapping to investigate the altered local and global functional connectivity (FC) of the cortex in PACG. METHODS: Forty-five PACG patients (53.28±10.79 years, 17 males/28 females) and 46 well-matched healthy controls (HCs) (52.67±11.01 years,18 males/28 females) received resting-state fMRI scans. All PACG patients finished complete ophthalmologic examinations, including retinal nerve fiber layer thickness (RNFLT), intraocular pressure (IOP), average cup to disc ratio (A-C/D), and vertical cup to disc ratio (V-C/D). We calculated the between-group FCD difference for short-range and long-range in each voxel. Then, we generated the intrinsic FC of the seed region with the whole brain. Finally, correlations were investigated between FCD value of the altered regions and clinical variables. RESULTS: PACG patients showed increased short-range FCD in the left inferior frontal gyrus (IFG)/insula/parahippocampal gyrus and right IFG/insula (P

INTRODUCTION The efficacy of memantine for migraine remains controversial. We conduct a systematic review and meta-analysis to explore the influence of memantine versus placebo on treatment in migraine patients. METHODS We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through February 2020 for randomized controlled trials assessing the effect of memantine versus placebo on treatment efficacy in migraine patients. This meta-analysis is performed using the random-effect model. RESULTS Three randomized controlled trials are included in the meta-analysis. Overall, compared with control group in migraine patients, memantine treatment is associated with substantially reduced monthly attack frequency (mean difference [MD], -2.14; 95% confidence interval [CI], -2.83 to -1.46; P < 0.00001), number of migraine days (MD, -4.17; 95% CI, -6.40 to -1.93; P = 0.0003) and Migraine Disability Assessment (MD, -5.63; 95% CI, -6.46 to -4.79; P < 0.00001), but demonstrates no obvious influence on acute pain medications (MD, -1.23; 95% CI, -4.63 to 2.17; P = 0.48). CONCLUSIONS Memantine treatment may benefit to the control of migraine.

Objective Using functional connectivity density (FCD) mapping measured by resting-state functional magnetic resonance imaging (rs-fMRI), an ultrafast data-driven graph theory approach, we attempted to study the abnormalities in neural activity of young survivors of acute lymphoblastic leukemia (ALL) and to explore the neuropathological evidence of chemotherapy-related cognitive impairment of patients. Methods Twenty young survivors of ALL and 18 well-matched healthy controls (HCs) were recruited in this study. All ALL patients and healthy controls underwent rs-fMRI scans and completed neurocognitive testing. The between-group differences in short-range and long-range FCD were calculated by the option of degree centrality (DC) in MATLAB software after preprocessing. The correlations between the FCD value and each of the neurocognitive outcomes were analyzed in the ALL patients. Results The group-averaged FCD maps showed similar spatial patterns between the two groups. Compared with the HCs, ALL patients showed decreased long-range FCD in regions of the bilateral lingual gyrus, cingulate cortex, hippocampal gyrus, and right calcarine fissure. Simultaneously, decreased regions in the short-range FCD map were the bilateral lingual gyrus, cingulate cortex, parahippocampal gyrus and right calcarine fissure. Increased functional connectivity (FC) was observed between the region with decreased long-range FCD and the posterior cerebellar lobe, and decreased FC was observed between the region and the middle occipital gyrus, cuneus and lingual gyrus. Thus, there existed no brain areas with increased FCD. The decreased short-range FCD value of ALL patients was positively correlated with the score on the Digit Span Test (Forward), and the increased FC value was negatively correlated with the score on the Trail Making Test part A. Conclusion Our results suggest the altered functional connectivity of young survivors of ALL in the posterior region of the brain and posterior lobe of the cerebellum. Alterations in spontaneous neuronal activity seem to parallel the neurocognitive testing, which indicates that the rs-fMRI could be used as a neuroimaging marker for neurological impairment in ALL patients.

Palliative care might be beneficial to heart failure. However, the results remain controversial. We conducted a systematic review and meta-analysis to explore the effect of palliative care on heart failure.PubMed, Embase, Web of Science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of palliative care versus usual care on heart failure were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was readmission. Meta-analysis was performed using random-effect model.Five RCTs involving 545 patients were included in the meta-analysis. Overall, compared with control intervention, palliative care intervention was found to significantly reduce the readmission [Std. mean difference = 0.79; 95% confidence intervals (CI) = 0.23 to 1.35; P = 0.006], Edmonton Symptom Assessment Scale (ESAS) (Std. mean difference = -2.5; 95% CI = -4.39 to -0.62; P = 0.009), and PHQ-9 (Std. mean difference = -1.16; 95% CI = -1.73 to -0.58; P < 0.005), as well as improve heart failure questionnaire (Std. mean difference = 4.46; 95% CI = 3.44 to 5.47; P < 0.005), but had no influence on mortality (RR = 1.54; 95% CI = 0.80 to 2.96; P = 0.19) and quality of life questionnaire (Std. mean difference = 1.81; 95% CI = -0.14 to 3.77; P = 0.07).Compared with control intervention, palliative care intervention was found to significantly reduce readmission, ESAS, PHQ-9, and improve heart failure questionnaire, but showed no influence on mortality and quality of life questionnaire in patients with heart failure.

Aim Acute liver failure (ALF) is a life-threatening acute liver injury (ALI) with high mortality. Gensenoside Rg1 (G-Rg1) effects on Lipopolysaccharide- (LPS-) and d -galactose-(D-gal-) induced ALI, but its effects on ALF remained unclear. This paper aimed to validate its possible efficacy on ALF prevention. Methods For in vivo studies, histological examination was performed using hematoxylin-eosin (H&E) staining, and alanine aminotransferase (ALT), aspartate aminotransminase (AST), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) contents were measured. Levels of inflammatory cytokines tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) were quantified via enzyme-linked immunosorbent assay (ELISA). Human bronchial epithelial cell line BEAS-2B was used for ALF model in vitro and its viability was measured by MTT assay. Expressions of high mobility group box 1 (HMGB1) and toll-like receptor 4-Nuclear Factor-κB (TLR4-NF-κB) pathway-related proteins were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot as needed. Results G-Rg1 relieved LPS- and D-gal-induced hepatic injury, and reduced ALT, AST and MDA levels but upregulated SOD and GSH levels, with downregulation on TNF-α and IL-6 levels. Expressions of HMGB1, TLR4 and NF-κB pathway-related proteins were also down-regulated after G-Rg1 treatment both in vivo and in vitro, while BEAS-2B cell viability was increased. However, overexpressed HMGB1 reversed the effects of G-Rg1 treatment in vitro. Conclusion G-Rg1 had a protective effect against LPS- and D-gal-induced ALF both in vitro and in vivo, which might be related to inhibited HMGB1-mediated TLR4-NF-κB Pathway. These discoveries suggested that G-Rg1 could be a potential agent for prevention against ALF.

Ni0.56+x/2Zn0.34Cu0.1Fe2.0-xO4-x (x = 0, 0.02, 0.04, 0.06, 0.08, 0.12) ferrites have been prepared by the solid-state reaction method. The Rietveld refinement of X-ray diffraction patterns, microstructure, static magnetic properties and ferromagnetic resonance (FMR) linewidth of NiCuZn ferrites have been analyzed by X-ray diffraction, scanning electron microscopy (SEM), B-H analyzer and electron spin resonance (ESR) spectrometer, respectively. The FMR linewidth was investigated by an approximate calculation based on spin wave approach. The results revealed that all the samples were a single NiCuZn spinel phase. With the increase of iron-deficient amount, the lattice parameter (a) displayed a decreasing trend. However, the bulk density first increased rapidly and then trended to go up slightly. The saturation magnetization of stoichiometric NiCuZn ferrites was much lower than that of iron-deficient samples. This phenomenon is ascribed to the combined effect between molecule magnetic moment and bulk density. The magnetocrystalline anisotropy constant, derived from the law of approach to saturation, has been discussed. The anisotropy and porosity linewidth broadening models were adopted to identify the linewidth contribution. The results manifested that the porosity linewidth broadening was much larger than the anisotropy linewidth broadening.

Palliative care might be beneficial to heart failure. However, the results remain controversial. We conducted a systematic review and meta-analysis to explore the effect of palliative care on heart failure.PubMed, Embase, Web of Science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of palliative care versus usual care on heart failure were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was readmission. Meta-analysis was performed using random-effect model.Five RCTs involving 545 patients were included in the meta-analysis. Overall, compared with control intervention, palliative care intervention was found to significantly reduce the readmission [Std. mean difference = 0.79; 95% confidence intervals (CI) = 0.23 to 1.35; P = 0.006], Edmonton Symptom Assessment Scale (ESAS) (Std. mean difference = -2.5; 95% CI = -4.39 to -0.62; P = 0.009), and PHQ-9 (Std. mean difference = -1.16; 95% CI = -1.73 to -0.58; P0.005), as well as improve heart failure questionnaire (Std. mean difference = 4.46; 95% CI = 3.44 to 5.47; P0.005), but had no influence on mortality (RR = 1.54; 95% CI = 0.80 to 2.96; P = 0.19) and quality of life questionnaire (Std. mean difference = 1.81; 95% CI = -0.14 to 3.77; P = 0.07).Compared with control intervention, palliative care intervention was found to significantly reduce readmission, ESAS, PHQ-9, and improve heart failure questionnaire, but showed no influence on mortality and quality of life questionnaire in patients with heart failure.

The polycrystalline Ni 0.56 Cu 0.10 Zn 0.34 Fe 2− x O 4−3/2 x ( x =0.00~0.14) ferrites have been prepared by conventional oxide ceramics process. The effects of Fe-deficiency content on magnetic properties and Brillouin function characteristics for NiCuZn ferrites have been investigated in details. With the increase of Fe-deficiency content, the opposite variation trend are observed for the saturation magntic induction B s and the coercivity H c . More importantly, based on the Neel molecular field theory, for the spinel ferrites which do not only contain Fe 3+ but also some other multiple magnetic ions (Ni 2+ and Cu 2+ ), the molecular field coefficients ω aa , ω bb and ω ab= ω ba are calculated by non-linear fitting method, and the Curie temperature T c formula has been modified. With the increase of Fe-deficiency content, the values of ω aa and ω bb increase gradually, however, the value of ω ab = ω ba has a contrary trend which results in the decrease of the Curie temperature. In addition, the fitting Curie temperatures values are coincided well with the Curie temperatures calculated by the modified formula.

Greater occipital nerve (GON) block has some potential in treating migraine. We conduct a systematic review and meta-analysis to investigate the impact of GON block on pain management of migraine. We have systematically searched randomized controlled trials (RCTs) assessing the efficacy of GON block versus placebo for migraine in various databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases. The primary outcome is pain intensity. Meta-analysis is performed using the random-effect model. Seven RCTs are included in the meta-analysis. Compared with control intervention in migraine patients, GON block intervention can significantly reduce pain intensity (Mean difference = −1.24; 95% CI = −1.98 to −0.49; P = 0.001) and analgesic medication consumption (Mean difference = −1.10; 95% CI = −2.07 to −0.14; P = 0.02), but has no remarkable impact on head duration (Mean difference = −6.96; 95% CI = −14.09 to 0.18; P = 0.0.06) and adverse events (RR = 0.93; 95% CI = 0.52 to 1.65; P = 0.80). GON block intervention is able to significantly reduce pain intensity and analgesic medication consumption in migraine patients.

BACKGROUND The efficacy of dexketoprofen for migraine attack remains controversial. We conduct a systematic review and meta-analysis to explore the influence of dexketoprofen supplementation versus placebo on pain control in migraine attack patients. METHODS We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through March 2019 for randomized controlled trials (RCTs) assessing the effect of dexketoprofen supplementation versus placebo on pain control for migraine attack patients. This meta-analysis is performed using the random-effect model. RESULTS Five RCTs involving 794 patients are included in the meta-analysis. Overall, compared with control group for migraine attack, dexketoprofen supplementation is associated with substantially increased pain free at 2 hours (RR = 1.90; 95% CI = 1.43-2.53; P

Rationale:Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disease identified with diffusion-weighted imaging (DWI) high-intensity signal in magnetic resonance imaging (MRI). The disappearance of the abnormal signal is extremely rare.Patient concerns:We present the

A gas chromatographic (GC) method was established for the determination of lambda-cyhalothrin residue in tea and soil. Tea and soil samples were extracted with hexane, separated by capillary column and determined by gas chromatography-electron capture detector (GC-ECD). The average recoveries of lambda-cyhalothrin in tea and soil were 89.0% - 94.1% and 89.8% - 94.7%, respectively at the spiking levels of 0.02 to 2.00 mg/kg. The corresponding relative standard deviations (RSDs, n = 5) were 3.0% -4.9% and 2.5% -4.2%, respectively. The limit of detection (S/N = 3) was 0.002 mg/kg for lambda-cyhalothrin. The degradations of 2.5% lambda-cyhalothrin microemulsion in tea and soil in Changsha, Hunan were investigated and the degradation equations were Y = 3.199 6e(-0.339 4x) and Y = 0.122 4e(-0.103 6x) with the correlation coefficients of 0.995 6 and 0.924 7, respectively. The half-lives of lambda-cyhalothrin in tea and soil were 2.04 days and 6.69 days, respectively.

In this paper, nanocrystalline FeNi alloy powders with different particle size were prepared by two-step mechanical alloying (MA), the first step of the processes is FeNi nanocrystalline alloying and the second step modifies particle size. As-milled powders were randomly dispersed in paraffin at a weight ratio of 5:1 for microwave complex permeability test and comparision in the frequency range of 0.5–18 GHz. It is observed and discussed that microwave complex permeability is prominently affected by FeNi microstructure and particle size. In this work, Fe 0.85 Ni 0.15 nanocrystalline powders exhibit high value of complex permeability in 1–10 GHz, and the sample with particle size of 2.34 μm possesses the maximum value as μ′=6.32 at 1.81 GHz, μ′′=3.45 at 4.09 GHz. This value may be useful for thin-thickness and wide-band microwave absorber.

Z-type hexaferrite (Ba 3 (Co 0.4 Zn 0.6 ) 2 Fe 23.4 O 41 ) with BST(Ba 0.5 Sr 0.5 TiO 3 ) additive was prepared by conventional solid-state reaction method. We have investigated the effects of BST additive on the complex permeability, permittivity and microwave absorption in the range of 1 MHz–1 GHz. The results from XRD and SEM indicate that as the amount of BST increases, the major phase changes to Z-phase, simultaneously M-phase and perovskite phase appear, and grain size increases. When the weight percent of BST additive in Z-type hexaferrite varied from 0% to 1.5%, the BST additive not only improved complex permeability and complex permittivity, but also provided broadband reflectivity characteristics. Meanwhile the minimum reflection point shifts to lower frequency with increase of BST content.

An analytical method for the determination of nitenpyram residue in cabbage and soil using gas chromatography was established. The nitenpyram residue was extracted from cabbage and soil with acetone-water (4 : 1, v/v), cleaned up by a Florisil column, and then detected by gas chromatography-electron capture detection (GC-ECD). At the spiked level range from 0.02 to 2.00 mg/kg, the average recoveries of nitenpyram were 88.73%-94.3% and 90.82%-96.27% with the relative standard deviations (RSDs) of 3.09%-7.39% and 2.01%-4.92% in cabbage and soil, respectively. The limit of detection of nitenpyram was 0.02 mg/kg. The method is fast, sensitive, simple, reproducible and practical for the determination of nitenpyram residue in environmental systems.

A gas chromatographic (GC) method was established for the determination of lambda-cyhalothrin residue in tea and soil. Tea and soil samples were extracted with hexane, separated by capillary column and determined by gas chromatography-electron capture detector (GC-ECD). The average recoveries of lambda-cyhalothrin in tea and soil were 89.0% - 94.1% and 89.8% - 94.7%, respectively at the spiking levels of 0.02 to 2.00 mg/kg. The corresponding relative standard deviations (RSDs, n = 5) were 3.0% -4.9% and 2.5% -4.2%, respectively. The limit of detection (S/N = 3) was 0.002 mg/kg for lambda-cyhalothrin. The degradations of 2.5% lambda-cyhalothrin microemulsion in tea and soil in Changsha, Hunan were investigated and the degradation equations were Y = 3.199 6e(-0.339 4x) and Y = 0.122 4e(-0.103 6x) with the correlation coefficients of 0.995 6 and 0.924 7, respectively. The half-lives of lambda-cyhalothrin in tea and soil were 2.04 days and 6.69 days, respectively.

Based on Neel's two-sublattice collinear model, the relationship between Curie temperature Tc and temperature characteristics of Brillouin function for NiCuZn ferrites has been studied by nonlinear fitting calculation method. According to the tetrahedral A sites and the octahedral B sites of spinel structure model which do not only contain Fe3+ but also some other multiple magnetic ions (Ni2+and Cu2+), molecular-field coefficients ωaa, ωbb, and ωab = ωba have been calculated; furthermore, the ferrimagnetism and paramagnetism Curie temperature Tc calculation formula has been modified, respectively. The magnetic moment versus temperature T (below the Curie temperature Tc) and the reciprocal of paramagnetism magnetic susceptibility 1/χm versus temperature T (beyond the Curie temperature Tc) have been investigated, respectively. The values of the calculated ferrimagnetism Curie temperature are very close to the values of the testing Curie temperature, and with the same zinc content t, the values of paramagnet...