[Investigation and analysis of acute poisoning of organic fluorine mixed gas in a fluorine polymerization plant].

In January 2021, an acute chemical poisoning incident occurred at a fluorine polymerization plant. Through the analysis of the occupational health situation of the enterprise, combined with the clinical manifestations of the poisoned patients and the laboratory examination results, it was determined that the incident was an acute poisoning incident caused by the inhalation of organic fluorine mixed gas in the fluorine polymerization plant. Subsequently, it was clarified that the accident was caused by the illegal operation of the employees of the fluorine polymerization plant, which caused the discharge of the organic fluorine mixed gas containing high concentration of octafluoroisobutene, resulting in the poisoning of the on-site construction personnel. In order to avoid the occurrence of similar incidents, enterprises should implement the main responsibility of safety production, regularly organize supervision and inspection, eliminate illegal operations, conduct safety education and training for the staff of the unit and outsourced staff, and improve the emergency rescue ability of sudden poisoning incidents.

Following the Nonthermal Phase Transition in Niobium Dioxide by Time-Resolved Harmonic Spectroscopy.

Photoinduced phase transitions in correlated materials promise diverse applications from ultrafast switches to optoelectronics. Resolving those transitions and possible metastable phases temporally are key enablers for these applications, but challenge existing experimental approaches. Extreme nonlinear optics can help probe phase changes, as higher-order nonlinearities have higher sensitivity and temporal resolution to band structure and lattice deformations. Here the ultrafast transition from the semiconducting to the metallic phases in polycrystalline thin-film NbO_{2} is investigated by time-resolved harmonic spectroscopy. The emission strength of all harmonic orders shows a steplike suppression when the excitation fluence exceeds a threshold (∼11-12 mJ/cm^{2}), below the fluence required for the thermal transition-a signature of the nonthermal emergence of a metallic phase within 100±20 fs. This observation is backed by full ab initio simulations as well as a 1D chain model of high-harmonic generation from both phases. Our results demonstrate femtosecond harmonic probing of phase transitions and nonthermal dynamics in solids.

[Long-term mortality risk of valvular heart disease adults over 35 years old in Chinese communities].

Objective: To investigate the risk and influencing factors of long-term mortality of valvular heart disease (VHD) adults aged 35 years and over in Chinese communities. Methods: A cohort study was carried out. The data of the subjects who underwent echocardiography were collected from the Chinese Hypertension Survey between 2012 and 2015 and survival outcomes were followed up between 2018 and 2019. Kaplan-Meier survival curves were plotted and compared using log-rank test. Cox proportional hazards models were used to analyze the influence of VHD on mortality. Results: During an average follow-up time of (4.6±0.9) years, a total of 23 237 participants (10 881 males and 12 356 females) were pooled into the final analysis from 5 eastern, 5 central, and 4 western provinces, cities and autonomous regions in China, with a mean age of (56.9±13.2) years. Among the included participants, 1 004 had VHD (467 males and 537 females), with a mean age was of (68.1±12.6) years. In the Kaplan-Meier analysis, participants with VHD had a significantly increased risk of all-cause mortality (log-rank χ2=351.82, P<0.001) and cardiovascular mortality (log-rank χ2=284.14, P<0.001) compared with those without VHD. Multivariate Cox regression analysis showed that compared with those without VHD, the participants with rheumatic VHD had a 45% increased risk of all-cause mortality (HR=1.45, 95%CI: 1.12-1.89) and degenerative VHD increased the risk of cardiovascular mortality by 69% (HR=1.69, 95%CI: 1.19-2.38). The risk factors of cardiovascular mortality for VHD were age 55 years and over (55-<75 years: HR=4.93, 95%CI: 1.17-20.85;≥75 years: HR=11.92, 95%CI: 2.85-49.80) and diabetes mellitus (HR=1.71, 95%CI: 1.00-2.93). Conclusions: VHD is a risk factor of all-cause mortality and cardiovascular mortality among adults aged 35 years and over. Age 55 years and over and diabetes mellitus are adverse prognostic factors for patients with VHD.

[Analysis of families with fetal congenital abnormalities but negative prenatal diagnosis by whole exome sequencing].

Objective: To evaluate the value of whole exome sequencing (WES) in prenatal clinical application. Methods: A total of 1 152 cases of congenital abnormal [including structural malformation, nuchal translucency (NT) thickening and intrauterine growth restriction] with traditional prenatal diagnosis [including G-band karyotype analysis and chromosome microarray analysis (CMA)] negative were analyzed. The congenital abnormal fetuses were divided into retrospective group and prospective group according to the time of WES detection, that is whether the pregnancy termination or not. According to the specific location of fetal malformation and their family history, the cohort was divided into subgroups. The clinical prognosis of all fetuses were followed up, and the effect of WES test results on pregnancy decision-making and clinical intervention were analyzed. According to the follow-up results, the data of fetuses with new phenotypes in the third trimester or after birth were re-analyzed. Results: Among 1 152 families who received WES, 5 families were excluded because of nonbiological parents. Among the remaining 1 147 families, 152 fetuses obtained positive diagnosis (13.3%,152/1 147), including 74 fetuses in the retrospective group (16.1%,74/460) and 78 fetuses in the prospective group (11.4%,78/687). In fetuses with negative CMA and G-band karyotype analysis results but new phenotypes in the third trimester or after birth, the positive rate by WES data re-analysis was 4.9% (8/163). A total of 34 (21.3%, 34/160) fetuses were directly affected by the corresponding positive molecular diagnosis. Among 68 cases of live births with diagnostic variation grade 4, 29 cases (42.7%, 29/68) received appropriate medical intervention through rapid review of WES results. Conclusions: WES could increase the detection rate of abnormal fetuses with negative G-banding karyotype analysis and CMA by 13.3%. Prenatal WES could guide pregnancy decision-making and early clinical intervention. It might be an effective strategy to pay attention to the special follow-up of the third trimester and postnatal fetus and to re-analyze the WES data.

The effect of acetylation on the protein stability of BmApoLp-III in the silkworm, Bombyx mori.

Acetylation is an important, reversible posttranslational modification to a protein. In a previous study, we found that there were a large number of acetylated sites in various nutrient storage proteins of the silkworm haemolymph. In this study, we confirmed that acetylation can affect the stability of nutrient storage protein Bombyx mori apolipophorin-III (BmApoLp-III). First, the expression of BmApoLp-III could be upregulated when BmN cells were treated with the deacetylase inhibitor panobinostat (LBH589); similarly, the expression was downregulated when the cells were treated with the acetylase inhibitor C646. Furthermore, the increase in acetylation by LBH589 could inhibit the degradation and improve the accumulation of BmApoLp-III in BmN cells treated with cycloheximide and MG132 respectively. Moreover, we found that an increase in acetylation could decrease the ubiquitination of BmApoLp-III and vice versa; therefore, we predicted that acetylation could improve the stability of BmApoLp-III by competing for ubiquitination and inhibiting the protein degradation pathway mediated by ubiquitin. Additionally, BmApoLp-III had an antiapoptosis function that increased after LBH589 treatment, which might have been due to the improved protein stability after acetylation. These results have laid the foundation for further study on the mechanism of acetylation in regulating the storage and utilization of silkworm nutrition.

Simultaneous Nodal Superconductivity and Time-Reversal Symmetry Breaking in the Noncentrosymmetric Superconductor CaPtAs.

By employing a series of experimental techniques, we provide clear evidence that CaPtAs represents a rare example of a noncentrosymmetric superconductor which simultaneously exhibits nodes in the superconducting gap and broken time-reversal symmetry (TRS) in its superconducting state (below T_{c}≈1.5 K). Unlike in fully gapped superconductors, the magnetic penetration depth λ(T) does not saturate at low temperatures, but instead it shows a T^{2} dependence, characteristic of gap nodes. Both the superfluid density and the electronic specific heat are best described by a two-gap model comprising of a nodeless gap and a gap with nodes, rather than by single-band models. At the same time, zero-field muon-spin relaxation spectra exhibit increased relaxation rates below the onset of superconductivity, implying that TRS is broken in the superconducting state of CaPtAs, hence indicating its unconventional nature. Our observations suggest CaPtAs to be a new remarkable material that links two apparently disparate classes, that of TRS-breaking correlated magnetic superconductors with nodal gaps and the weakly correlated noncentrosymmetric superconductors with broken TRS, normally exhibiting only a fully gapped behavior.

Phase Space Dynamics of a Plasma Wakefield Dechirper for Energy Spread Reduction.

Plasma-based accelerators have made impressive progress in recent years. However, the beam energy spread obtained in these accelerators is still at the ∼1% level, nearly one order of magnitude larger than what is needed for challenging applications like coherent light sources or colliders. In plasma accelerators, the beam energy spread is mainly dominated by its energy chirp (longitudinally correlated energy spread). Here we demonstrate that when an initially chirped electron beam from a linac with a proper current profile is sent through a low-density plasma structure, the self-wake of the beam can significantly reduce its energy chirp and the overall energy spread. The resolution-limited energy spectrum measurements show at least a threefold reduction of the beam energy spread from 1.28% to 0.41% FWHM with a dechirping strength of ∼1 (MV/m)/(mm pC). Refined time-resolved phase space measurements, combined with high-fidelity three-dimensional particle-in-cell simulations, further indicate the real energy spread after the dechirper is only about 0.13% (FWHM), a factor of 10 reduction of the initial energy spread.

[Analysis of spatial-temporal distribution of pesticide poisoning in Quzhou, 2013-2017].

Objective: To analysis the epidemic and spatial characteristics of pesticide poisoning in Quzhou during 2013-2017, and to provide scientific basis for the prevention and control of influenza in Quzhou in the future. Methods: The incidence data of pesticide poisoning from January 1, 2013 to December 31, 2017 in Quzhou collected from China Information System For Disease Control And Prevention. The descriptive analysis conducted by using SPSS18.0 software, and the Sa T Scan 9.2 software was used to complete space-time scan. Finally, ArcMap10.2 software was used to visualize the results. Results: There were 1819 cases of pesticide poisoning in Quzhou from 2007 to 2016, among which 298 cases were reported for productive poisoning, the incidence peak was from August to September, the highest number of patients in productive poisoning was in the age group of 46-60 years old and over 61 years old, with 109 patients in each group, and the number of male patients was significantly higher than that of female (χ(2)=63.857, P<0.01) . 1521 cases of non-productive pesticide poisoning were reported, among which the proportion of suicide poisoning (57.65%) was far higher than that of accidental poisoning (28.97%) , the number of female suicide poisoning was higher than that of male (χ(2)=5.510, P=0.019) , the proportion of accidental poisoning was the highest in the ≤15 years age group (89.00%, 89/100) , furthermore the number of suicide poisoning was the highest in the ≥61 years age group (314) . The incidence of pesticide poisoning could be detected by temporal-spatial scanning statistics, the time clustering is from August to September, the spatial clustering is in Jiangshan city, there are consistent with the descriptive of pesticide poisoning. Conclusion: The pesticide poisoning in Quzhou is mainly caused by non-productive suicide poisoning, and the spatial clustering is in Jiangshan city. Relevant departments should carry out targeted prevention and control measures according to the different characteristics of pesticide poisoning in clustered and non-clustered areas.

Whole exome sequencing as a diagnostic adjunct to clinical testing in fetuses with structural abnormalities.

OBJECTIVES: To evaluate the diagnostic yield of prenatal whole exome sequencing (WES) for monogenic disorders in fetuses with structural malformations and normal results on cytogenetic testing, and to describe information on pathogenic variants that is provided by WES. METHODS: Karyotyping, chromosomal microarray analysis (CMA) and WES were performed sequentially on stored samples from a cohort of 3949 pregnancies with fetal structural abnormalities detected on ultrasound and/or magnetic resonance imaging, referred between January 2011 and December 2015. Diagnostic rates of the three techniques were investigated overall, for phenotypic subgroups and for proband-only vs fetus-mother-father samples. Information on pathogenic variants was identified by WES. RESULTS: Overall, 18.2% (720/3949) of fetuses had an abnormal karyotype. Pathogenic copy number variants were detected on CMA in 8.2% (138/1680) of fetuses that had a normal karyotype result. WES performed on a subgroup of 196 fetuses with normal CMA and karyotype results revealed the putative genetic variants responsible for the abnormal phenotypes in 47 cases (24%). The molecular diagnosis rates for fetus-mother-father and proband-only samples were 26.5% (13/49) and 23.1% (34/147), respectively. Variants of uncertain significance were detected in 12.8% (25/196) of fetuses, of which 22 were identified in the fetal proband-only group (15%; 22/147) and three in the fetus-mother-father group (6.1%; 3/49). The incidental finding rate was 6.1% (12/196). CONCLUSIONS: WES is a promising method for the identification of genetic variants that cause structural abnormalities in fetuses with normal results on karyotyping and CMA. This enhanced diagnostic yield has the potential to improve the clinical management of pregnancies and to inform better the reproductive decisions of affected families. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Modeling of Li diffusion in nanocrystalline Li-Si anode material.

To quantify the Li diffusion behavior in nanocrystalline anode materials for lithium-ion batteries (LIBs), a hybrid model of the first principles calculation and diffusion kinetics was developed. The dependence of the Li diffusion on the electronic structure, solute concentration, grain size and temperature was described for the nanocrystalline Li-Si system. In contrast to conventional polycrystalline materials in which the activation barrier for Li diffusion decreases with the increase of concentration before amorphization, there exists a coordination effect of the solute concentration and grain size on the Li diffusion in nanocrystalline materials. A maximum diffusion coefficient can be obtained in the nanocrystalline Li-Si by a combination of the concentration and grain size, which is increased by two orders of magnitude from that in the coarse-grained counterpart. The present work advanced the understanding of the Li diffusion mechanisms during lithiation/delithiation of LIBs and may facilitate the development of nanocrystalline anode materials.

[Relationship between overnight urinary sodium to potassium ratio and the risk of cardiovascular disease].

Objective: To explore the relationship between overnight urinary sodium to potassium ratio and the risk of cardiovascular disease (CVD). Methods: A subsample of 10 percent of the participants (35-59 years old) from the People's Republic of China-United States Collaborative Study of Cardiovascular and Cardiopulmonary Epidemiology (prospective survey) were used. Three consecutive overnight urine samples were collected in the autumn of 1983-1984 and the spring in 1985-1986, respectively. Urinary sodium and potassium were detected and calculated for 8 hours excretion. The occurrences of cardiovascular events were recorded in 2 years interval from 1987-1988 until December 31, 2005. Participants were divided into first ratio group, second ratio group, and third ratio group based on the tertiles of sodium to potassium ratio. Cox proportional hazard regression model was used to determine the relationship between sodium to potassium ratio and risk of CVD. In addition, participants were divided into 2 subgroups by the median of overnight urinary sodium and potassium, and then combined each other for 4 subgroups including low sodium-low potassium group, low sodium-high potassium group, high sodium-low potassium group, and high sodium-high potassium group, to explore the relationship between different sodium-potassium combinations and the risk of CVD. Results: A total of 954 participants were included in the final analysis, of whom 459 (48.1%) were males. There were 318 cases in the first, second and third ratio group, respectively. There were 347 cases in low sodium-low potassium group and high sodium-high potassium group, and 130 cases in low sodium-high potassium group and high sodium-low potassium group. After a median follow-up of 18.6 (18.3, 19.3) years, cardiovascular events occurred in 81 participants, including 64 stroke and 20 coronary heart disease events. Multivariate analysis showed that comparing with the first ratio group, the hazard ratios (HR) in the second and the third ratio groups were 2.04 (95%CI 1.06-3.95, P=0.034) and 2.07 (95%CI 1.07-4.03, P=0.032), respectively. The CVD risk in low sodium-low potassium group was 24% higher than the low sodium-high potassium group (reference), but this result did not reach statistical significant level (P=0.685). The risks in high sodium-high potassium group (HR=3.32, 95%CI 1.26-8.76,P=0.015) and high sodium-low potassium (HR=3.04, 95%CI 1.05-8.83, P=0.041) group were both significantly increased. Conclusions: Overnight urinary sodium to potassium ratio is positively correlated with the risk of cardiovascular events. High urinary sodium plays a more important role for the increased risk of cardiovascular events than low potassium.

Molecular cloning and differential expression of the glucocorticoid receptorgene in the estuarine tapertail anchovy Coilia nasus.

To understand the regulation of the glucocorticoid receptor gene (Gcr) during loading and transport stress in fish, the Gcr gene of Coilia nasus was cloned. Gcr in C. nasus is expressed strongly in the liver and muscle, and less stronglyin the gills, brain, spleen, intestine, trunk kidney, and head kidney. Gcr expression in both the liver and muscle was increased by loading and transport stress. NaCl reduced the death rate caused by loading and transport stress, and the expression of Gcr in liver and muscle differed significantly between the NaCl and non-NaCl groups. To investigate whether the elevated Gcr transcripts were translated into protein, proteins extracted from the liver and muscle were analyzed. In both tissues, C. nasus GCR protein expression patterns paralleled those of Gcr mRNA during stress.

Functional characterization of Bombyx mori nucleopolyhedrovirus mutant lacking late expression factor 9.

Baculoviridae is a family of invertebrate viruses with large double-stranded DNA genomes. Proteins encoded by some late expression factor (lef ) genes are involved in the regulation of viral gene expression. Lef-9 is one of four transcription-specific Lefs, which are components of the virus-encoded RNA polymerase, and can initiate and transcribe late and very late genes. As a multifunctional protein encoded by the Bombyx mori nucleopolyhedrovirus (BmNPV), Lef-9 may be involved in the regulation of viral propagation. However, the underlying mechanism remains unclear. To determine the role of lef-9 in baculovirus infection, lef-9-knockout virus (lef-9-KO-Bacmid virus) was constructed using the Red recombination system, and the Bac-to-Bac system was used to prepare lef-9-repaired virus (lef-9-Re-Bacmid virus). The lef-9-KO virus did not produce infectious viruses or show infection activity, while the lef-9-repaired virus recovered both. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis of the transcription levels in wild-type-Bacmid, lef-9-KO-Bacmid, and lef-9-Re-Bacmid viruses showed that the lef-9-KO bacmid had little effect on viral genome replication. However, the transcription levels of the early and late viral genes, lef-3, ie-1, vp39, and p10, were significantly lower in BmN cells transfected with lef-9-KO-Bacmids than in the controls. Electron microscopy showed no visible enveloped virions in cells transfected with lef-9-KO-Bacmids, while many mature virions in cells transfected with lef-9-Re-Bacmid and wt-Bacmid were present. Thus, lef-9 was not essential for viral genome replication, but significantly affected viral gene transcription and expression in all periods of cell life cycle.

[Analysis of long-term compliance to continuous positive airway pressure in patients with obstructive sleep apnea].

OBJECTIVE: To explore the continuous positive airway pressure (CPAP) therapy compliance in patients with obstructive sleep apnea (OSA). METHODS: This prospective study recruited a group of subjects from May 2009 to December 2013 who were diagnosed and had accepted CPAP treatment in Sleep Center of Guangdong General Hospital, and the patients were followed-up regularly for long-term and assessed the CPAP treatment compliance. The patients were diagnosed, had pressure titration and CPAP treatment through out of center sleep test. The subjects were followed-up for 1 st, 3rd, 6th, 12th month, and each year regularly after accepting the CPAP treatment in Sleep Center by face to face follow-up with specialist physicians. Physicians followed-up the patients' subjective symptoms, CPAP adherence, patient education and side effect solutions. The patients were classified into good and poor compliance groups, and statistical analysis was done between the two groups. RESULTS: There were 77 cases enrolled until December 2015, only 73 patients completed the study. The patients were followed-up about 2-6 years, the average was (3.93±1.29) years, the compliance accounted for 54.8% (40/73), and the average compliance was (4.02±1.87) hours/night. The trend of the long-term compliance showed that there was a gradual increase within the first 3 months of CPAP treatment and then the compliance decreased; it then increased gradually after the first two years. The good compliance group showed that the compliance increased gradually in the initial 3 months, and then fell; from the first year to the 3rd year, the compliance was stable; after the 3rd year there was a drop and the compliance tended to increase again after the 4th year. The poor compliance group showed the compliance had a downward trend from the beginning of the first two years, then after a brief rise, the compliance decreased linearly. Multivariate analysis showed that long-term compliance was not associated with age, daytime sleepiness (ESS), oxygen desaturation index (ODI), anxiety, depression (P>0.05), etc. However, it was associated with the time of the titration treatment (P<0.001), the time of the flow monitored (P<0.01) and the number of the pressure titration within one week (P<0.05). CONCLUSIONS: Long-term compliance shows a curve change, the increased compliance is related with the regular follow-up. Long-term compliance can be predicted by the degree of cooperation with the initial diagnosis and treatment.

The effect of BM67 gene deletion on Bombyx mori nuclear polyhedrosis virus replication.

Homologs of Bombyx mori nuclear polyhedrosis virus (BmNPV) Bm67 gene ORF67 have been found in the genome of all lepidopteran nuclear polyhedrosis viruses, but their function is still not very clear. In order to analyze it we employed a  bacmid harboring the complete BmNPV genome including the Bm67 gene and expressing infectious virus (wtBacmid) for the construction of its Bm67-deficient variant (Bm67-KO-Bacmid) using the Red recombination system and the Bm67-repaired variant (Bm67-Re-Bacmid) using the Bac-to-Bac system. By transfecting BmN cells with these bacmids we demonstrated that the Bm67-deficient virus did not generate infectious virus, while the repaired virus restored its infectivity, indicating that the Bm67 gene is essential for the formation of infectious budding virus (BV). Electron microscopy of BmN cells transfected with the abovementioned bacmids showed many mature rodshaped virus particles in both wtBacmid- and Bm67-Re-Bacmid-transfected cells but none in Bm67-KO-Bacmid-transfected ones. Moreover, the real-time RT-PCR showed that the deletion of Bm67 from wtBacmid significantly reduced the levels of viral genomic DNA and transcripts of viral early genes dnapol, ie-1 and lef-3 but not those of transcripts of late gene vp39 and very late gene p10. The finding that the Bm67-deficient virus generated reduced levels of infectious virus and transcripts of early dnapol gene but not those of late genes indicates that the Bm67 gene is essential for BmNPV replication.

Sunscreen photopatch testing: a series of 157 children.

BACKGROUND: Photoprotection including sunscreen use in children is encouraged by health campaigns. While sunscreen chemicals are common causes of photoallergic (PA) contact reactions in adults, limited data are available in children. OBJECTIVES: To assess the frequency of PA and contact allergy (CA) to sunscreens in children aged < 18 years undergoing investigation for suspected photosensitivity. METHODS: Retrospective analysis of data on children who underwent photopatch testing to a standard series of nine ultraviolet (UV) filters and to sunscreen products in a single photoinvestigation centre (2000-11). Duplicate series of UV filters and the children's own sunscreen products were applied to the back, with readings taken at sample removal, and at 24 and 48 h after 5 J cm(-2) UVA exposure of one series. RESULTS: The analysis comprised 157 children (aged 3-17 years, 69 male and 88 female). In total 10 children (6·4%) showed positive photopatch responses to UV filters and/or their sunscreen products (4·5% to UV filters, 5·7% to their sunscreen products). The responsible UV filters most often identified were benzophenone-3 and octyl methoxycinnamate. Additionally, CA reactions were observed in nine children (5·7%), with 16 children (10·2%) showing PA and/or CA to UV filters and/or sunscreen products. CONCLUSIONS: This is the largest series of photopatch testing reported in children, and shows that both sunscreen PA and CA are quite frequent in those undergoing photoinvestigation. Photopatch testing should be considered in children presenting with features of photosensitivity.

Transmission of avian influenza A(H7N9) virus from father to child: a report of limited person-to-person transmission, Guangzhou, China, January 2014.

We investigated a possible person-to-person transmission within a family cluster of two confirmed influenza A(H7N9) patients in Guangzhou, China. The index case, a man in his late twenties, worked in a wet market that was confirmed to be contaminated by the influenza A(H7N9) virus. He developed a consistent fever and severe pneumonia after 4 January 2014. In contrast, the second case, his five-year-old child, who only developed a mild disease 10 days after disease onset of the index case, did not have any contact with poultry and birds but had unprotected and very close contact with the index case. The sequences of the haemagglutinin (HA) genes of the virus stains isolated from the two cases were 100% identical. These findings strongly suggest that the second case might have acquired the infection via transmission of the virus from the sick father. Fortunately, all 40 close contacts, including the other four family members who also had unprotected and very close contact with the cases, did not acquire influenza A(H7N9) virus infection, indicating that the person-to-person transmissibility of the virus remained limited. Our finding underlines the importance of carefully, thoroughly and punctually following-up close contacts of influenza A(H7N9) cases to allow detection of any secondary cases, as these may constitute an early warning signal of the virus's increasing ability to transmit from person-to-person.

Magnesium intake and incidence of stroke: meta-analysis of cohort studies.

BACKGROUND AND AIMS: Prospective cohort studies are inconsistent regarding the association between magnesium intake and the risk of stroke. The objective was to perform a meta-analysis to summarise the relationship between magnesium intake and risk of stroke in observational studies. METHODS AND RESULTS: We searched the PubMed and EMBASE databases for studies conducted from 1966 through August 2011. Prospective studies that provided relative risk (RR) estimates with 95% confidence intervals (CIs) for the association between magnesium intake and the risk of total stroke incidence or mortality were included. Data were independently abstracted by two investigators using a standardised protocol. Study-specific risk estimates were combined by using a random effects model. A total of eight studies, with 8367 stroke cases among 304,551 participants, were included in the meta-analysis. The summary RR indicated a significant association between the highest magnesium intake and reduced risk of total stroke (summary RR: 0.89; 95% CI: 0.82, 0.97); our dose-response analysis showed a borderline inverse association between magnesium intake and total stroke risk (an increment of 100 mg day(-1); summary RR: 0.98; 95% CI: 0.95, 1.00). Subgroup analyses suggested a significant inverse association between highest magnesium intake and the risk of ischaemic stroke (summary RR: 0.88; 95% CI: 0.80, 0.98). CONCLUSION: The present meta-analysis of prospective cohorts suggests that higher magnesium intake is associated with reduced risk of total and ischaemic stroke. However, well-designed randomised controlled trials are needed to draw a definitive conclusion.