Objective:To investigate the magnetic resonance imaging (MRI) features of non-midline atypical medulloblastoma (MB) in children and analyze the causes of misdiagnosis, so as to improve the understanding and diagnosis of MB.Methods:The clinical and imaging data of 12 cases with non-midline atypical MB confirmed by pathology in Hunan Children′s Hospital from September 2018 to August 2023 were retrospectively analyzed. 12 cases underwent MRI plain scan, 11 cases underwent enhanced scan, and 10 cases underwent diffusion weighted imaging (DWI) and magnetic sensitivity weighted imaging (SWI). The location, morphology, peritumoral edema, size, signal characteristics (cystic lesion or hemorrhage), diffusion and enhancement of the tumor were observed, and the causes of misdiagnosis were analyzed.Results:Among the 12 cases, 9 cases were single, 4 cases were located in the cerebellar hemisphere, 2 cases were in the cerebellopontine angle (CPA), 2 cases were in the brain stem and CPA, and 1 case was in the left parietal lobe. There were 3 cases of multiple lesions, 1 case was located in the right pontine arm and cerebellar hemisphere (2 masses), 1 case was multiple lesions in bilateral cerebellar hemisphere, and 1 case was multiple nodular lesions in the cerebellar vermis mass and left cerebellar hemisphere. 6 cases were irregular in shape and 6 cases were quasi-circular. There were 3 cases without cystic change and 9 cases with varying degrees of cystic change (5 with large cystic change and 4 with small cystic change). 3 cases of hemorrhage, no calcification, 10 cases of DWI showed varying degrees of limited diffusion; 11 cases of enhanced scanning showed mild to obvious enhancement; There were 2 cases without peritumoral edema and 10 cases with mild to moderate peritumoral edema. There were 11 cases with supratentorial hydrocephalus and interstitial cerebral edema, and 1 case without hydrocephalus. 5 cases complicated with subtonsillar hernia; 9 cases were misdiagnosed before operation. Among them, 3 cases were misdiagnosed as high-grade glioma, 3 as low-grade glioma (1 of which was diagnosed as hair-cell astrocytoma), 2 as ependymoma, and 1 as atypical teratoma/rhabdomyoma.Conclusions:The MRI manifestations of non-midline atypical MB in children are varied. Combined with the location of the disease, age and focal signal characteristics, non-midline atypical MB can be included in the diagnostic range after the exclusion diagnosis, which can improve the preoperative diagnosis accuracy of this disease.

In recent years,the prevalence of porcine infectious pleuropneumonia caused by Actinoba-cillus pleuropneumoniae(APP)has significantly increased in large-scale pig farms in China.The i-solation,identification,and biological characteristic testing of newly prevalent strains have impor-tant clinical significance.This study isolated four suspected APP strains(named XB2T-56,JMTLP-443,YD-THB-755,SYZJ-291)from lung samples of pig farms suspected of outbreaks of porcine infectious pleuropneumonia in Hubei Province.They were identified by PCR amplification,and multiplex PCR serological typing,the biological properties were tested by detecting the growth a-bility,hemolytic activity and biofilm forming ability.The drug resistance of the strains was ana-lyzed by drug sensitivity testing,and the virulence of one strain(XB2T-56)in mice and piglets was evaluated.The PCR identification result showed that all four clinical isolates were APP serotype 15 strains.These four strains grew slower than serotype 1 standard strains,had weaker hemolytic activity,but could form stronger biofilms.These strains are all less sensitive to cephalosporin,tylo-sin,sulfamethoxazole,and doxycycline,but sensitive to cefotaxime and enrofloxacin.The mice and piglet infection experiments showed that the isolated strain XB2T-56 has strong virulence.Artifi-cial intranasal infection causes acute death in piglets,with typical symptoms of pleuropneumonia in the lungs,and serotype 15 strains can be isolated from the lesion site.This study indicates that the APP serotype 15 strain has strong virulence,providing new date for the clinical epidemiological characteristics of APP.

Objective:To investigate the clinical manifestations of medically refractory hereditary movement disorders in children and the efficacy of deep brain stimulation (DBS).Methods:A case series study.The clinical and follow-up data of 20 children with medically refractory hereditary movement disorders who underwent DBS treatment at the Neurology and Functional Neurosurgery Departments of Beijing Children′s Hospital, Capital Medical University, from July 2018 to April 2024, were retrospectively analyzed.The severity of movement disorder symptoms and surgical effects were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale Movement(BFMDRS-M) or the Unified Parkinson′s Disease Rating Scale Ⅲ(UPDRS Ⅲ).Results:There were 12 males and 8 females among the 20 children, with an onset age ranging from 4 months to 12 years and 5 months.Fourteen patients had hereditary dystonia, which is related to KMT2B in 11 patients, TOR1A in 2 patients and SGCE in 1 patient.Two patients had choreoathetosis, which is related to ADCY5-related familial movement disorders.Two patients had early-onset Parkinson′s disease, which is related to ATP6AP2 in 1 patient and VPS13C in 1 patient.Two patients had neurodevelopmental disorders with involuntary movements, which is related to GNAO1 in 1 patient, and the other patient was idiopathic.All the children were given oral Levodopa, Benzhexol, Baclofen, Tiapride Hydrochloride, Clonazepam alone or in combination.Three children showed obvious dyskinesia after Levodopa treatment.The symptoms of movement disorders in all children exhibited little to no improvement.Levetiracetam and Zonisamide had unstable effects in the treatment of myoclonia.DBS surgery was performed on all the patients aged from 3 to 16 years.Electrodes were successfully inserted into bilateral globus pallidus internus in 14 cases and bilateral subthalamic nuclei in 4 cases.The target was unknown in 2 cases.No surgery-related complications were observed.The patients were followed up for 3 months to 6 years, and the last follow-up age of the patients ranged from 5 years and 7 months to 22 years and 1 month.The rate of improvement in BFMDRS-M score was 37%-100% in 16 patients and >70% in 7 patients with hereditary dystonia.The rate of improvement in UPDRS Ⅲ score was 23% in 1 patient with VPS13C-related early-onset Parkinson′s disease. Conclusions:Childhood medically refractory hereditary movement disorders are a case series that exhibits significant phenotypic and genotypic heterogeneity.DBS surgery demonstrates significant efficacy for KMT2B-, TOR1A-, and SGCE-related hereditary movement disorders.

ObjectiveTo investigate the effects of Yiqi Wenyang Huoxue Lishui components on the cardiac function and mitochondrial energy metabolism in the rat model of chronic heart failure （CHF） and explore the underlying mechanism. MethodsThe rat model of CHF was prepared by transverse aortic constriction （TAC）. Eight of the 50 SD rats were randomly selected as the sham group， and the remaining 42 underwent TAC surgery. The 24 SD rats successfully modeled were randomized into model， trimetazidine （6.3 mg·kg^-1）， and Yiqi Wenyang Huoxue Lishui components （60 mg·kg^-1 total saponins of Astragali Radix， 10 mg·kg^-1 total phenolic acids of Salviae Miltiorrhizae Radix et Rhizoma， 190 mg·kg^-1 aqueous extract of Lepidii Semen， and 100 mg·kg^-1 cinnamaldehyde） groups. The rats were administrated with corresponding agents by gavage， and those in the sham and model groups were administrated with the same amount of normal saline at a dose of 10 mL·kg^-1 for 8 weeks. Echocardiography was used to examine the cardiac function in rats. Enzyme-linked immunosorbent assay was employed to determine the serum levels of N-terminal pro-B-type natriuretic peptide （NT-ProBNP）， hypersensitive troponin（cTnI）， creatine kinase （CK）， lactate dehydrogenase （LD）， free fatty acids （FFA）， superoxide dismutase （SOD）， and malondialdehyde （MDA）. The colorimetric assay was employed to measure the levels of adenosine triphosphate （ATP）， adenosine diphosphate （ADP）， and adenosine monophosphate （AMP） in the myocardial tissue. The pathological changes in the myocardial tissue were observed by hematoxylin-eosin staining and Masson staining. The Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase activities in the myocardial tissue were determined by the colorimetric assay. The ultrastructural changes of myocardial mitochondria were observed by transmission electron microscopy. Western blot was employed to determine the protein levels of ATP synthase subunit delta （ATP5D）， glucose transporter 4 （GLUT4）， and carnitine palmitoyltransferase-1 （CPT-1）. The mitochondrial complex assay kits were used to determine the activities of mitochondrial complexes Ⅰ， Ⅱ， Ⅲ， and Ⅳ. ResultsCompared with the sham group， the model group showed a loosening arrangement of cardiac fibers， fracture and necrosis of partial cardiac fibers， inflammatory cells in necrotic areas， massive blue fibrotic tissue in the myocardial interstitium， increased collagen fiber area and myocardial fibrosis， destroyed mitochondria， myofibril disarrangement， sparse myofilaments， and fractured and reduced cristae. In addition， the rats in the model group showed declined ejection fraction （EF） and fractional shortening （FS）， risen left ventricular end-diastolic diameter （LVIDd）， left ventricular end-systolic diameter （LVIDs）， left ventricular end-diastolic posterior wall thickness （LVPWd）， left ventricular end-systolic posterior wall thickness （LVPWs）， left ventricular end-diastolic volume （LVVOLd）， and left ventricular end-systolic volume （LVVOLs）， elevated levels of NT-ProBNP， cTnI， CK， MDA， FFA， and LD， lowered level of SOD， down-regulated protein levels of GLUT4 and CPT-1， decreased activities of Na⁺-K⁺-ATPase， Ca²⁺-Mg²⁺-ATPase， and respiratory complexes Ⅰ-Ⅳ， and declined levels of ATP5D， ATP， ADP， and AMP （P<0.05， P<0.01）. Compared with the model group， the Yiqi Wenyang Huoxue Lishui components and trimetazidine groups showed alleviated pathological damage of the mitochondria and mycardial tissue， risen EF and FS， declined LVIDd， LVIDs， LVPWd， LVPWs， LVVOLd， and LVVOLs， lowered levels of NT-ProBNP， cTnI， CK， MDA， FFA， and LD， elevated level of SOD， up-regulated protein levels of GLUT4 and CPT-1， increased activities of Na⁺-K⁺-ATPase， Ca²⁺-Mg²⁺-ATPase， and respiratory complexes Ⅰ-Ⅳ， and elevated levels of ATP5D， ATP， ADP， and AMP （P<0.05， P<0.01）. ConclusionYiqi Wenyang Huoxue Lishui components can improve the cardiac function， reduce myocardial injury， regulate glucose and lipid metabolism， optimize the utilization of substrates， and alleviate the damage of mitochondrial structure and function， thus improving the energy metabolism of the myocardium in the rat model of CHF.

ObjectiveTo explore the protective effect of Shengxiantang on cardiac function and myocardial microvascular injury in rats with chronic heart failure （CHF）. MethodsThe CHF rat model was prepared by aortic arch constriction （TAC）. Of the 72 SD rats， 8 were randomly selected as the sham operation group， where the chest was opened without ligating the aortic arch. The 40 successfully modeled rats were randomly divided into the model group， the Shengxiantang low-， medium-， and high-dose groups （5.1， 10.2， 20.4 g·kg^-1）， and the trimetazidine group （6.3 mg·kg^-1）， with 8 rats in each group. Drug administration began 4 weeks after modeling. The administration groups received the corresponding drugs by gavage， while the sham operation and model groups were given the same amount of distilled water for 8 consecutive weeks. Echocardiography was used to assess cardiac function. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of nitric oxide （NO）， endothelin （ET-1）， vascular endothelial growth factor （VEGF）， and von Willebrand factor （vWF）. Ultrastructural changes of microvessels were observed by transmission electron microscopy. Immunohistochemistry was used to detect the expression levels of ATP synthase subunit （ATP5D） and F-actin in myocardial tissue. Western blot was used to detect the expression levels of occludin， claudin， vascular endothelial cadherin （VE-Cadherin）， and zonula occludens-1 （ZO-1）. Microvessel density was measured by immunofluorescence staining. ResultsCompared with the sham operation group， the ejection fraction （EF） and left ventricular shortening fraction （FS） in the model group were significantly decreased （P<0.01）， while the left ventricular diastolic diameter （LVIDd）， left ventricular systolic diameter （LVIDs）， left ventricular end-diastolic posterior wall thickness （LVPWd）， left ventricular end-systolic posterior wall thickness （LVPWs）， left ventricular end-diastolic volume （LVVOLd）， and left ventricular end-systolic volume （LVVOLs） were significantly increased （P<0.01）. The levels of NO and VEGF were significantly decreased （P<0.01）， while the levels of ET-1 and vWF were significantly increased （P<0.01）. Under electron microscopy， the microvascular basement membrane was incomplete and the tight junctions were blurred. The expression levels of ATP5D， F-actin， occludin， claudin， ZO-1， and VE-Cadherin were significantly decreased （P<0.05， P<0.01）， and the relative density of microvessels was significantly reduced （P<0.05， P<0.01）. After intervention with Shengxiantang， the EF and FS of CHF rats significantly increased （P<0.01）， while the LVIDd， LVIDs， LVPWd， LVPWs， LVVOLd， and LVVOLs significantly decreased （P<0.01）. The levels of NO and VEGF significantly increased （P<0.01）， while the levels of ET-1 and vWF significantly decreased （P<0.01）. Under electron microscopy， the microvascular basement membrane was relatively complete and the tight junctions were more continuous. The expression levels of ATP5D， F-actin， occludin， claudin， ZO-1， and VE-Cadherin significantly increased （P<0.05， P<0.01）， and the relative density of microvessels significantly increased （P<0.01）. ConclusionShengxiantang can effectively improve the cardiac function of CHF rats， reduce microvascular endothelial injury， strengthen the connection between endothelial cells， and increase microvessel density， thereby protecting myocardial microvascular injury.

ObjectiveTo explore the protective effect of Shengxiantang on cardiac function and myocardial microvascular injury in rats with chronic heart failure （CHF）. MethodsThe CHF rat model was prepared by aortic arch constriction （TAC）. Of the 72 SD rats， 8 were randomly selected as the sham operation group， where the chest was opened without ligating the aortic arch. The 40 successfully modeled rats were randomly divided into the model group， the Shengxiantang low-， medium-， and high-dose groups （5.1， 10.2， 20.4 g·kg^-1）， and the trimetazidine group （6.3 mg·kg^-1）， with 8 rats in each group. Drug administration began 4 weeks after modeling. The administration groups received the corresponding drugs by gavage， while the sham operation and model groups were given the same amount of distilled water for 8 consecutive weeks. Echocardiography was used to assess cardiac function. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of nitric oxide （NO）， endothelin （ET-1）， vascular endothelial growth factor （VEGF）， and von Willebrand factor （vWF）. Ultrastructural changes of microvessels were observed by transmission electron microscopy. Immunohistochemistry was used to detect the expression levels of ATP synthase subunit （ATP5D） and F-actin in myocardial tissue. Western blot was used to detect the expression levels of occludin， claudin， vascular endothelial cadherin （VE-Cadherin）， and zonula occludens-1 （ZO-1）. Microvessel density was measured by immunofluorescence staining. ResultsCompared with the sham operation group， the ejection fraction （EF） and left ventricular shortening fraction （FS） in the model group were significantly decreased （P<0.01）， while the left ventricular diastolic diameter （LVIDd）， left ventricular systolic diameter （LVIDs）， left ventricular end-diastolic posterior wall thickness （LVPWd）， left ventricular end-systolic posterior wall thickness （LVPWs）， left ventricular end-diastolic volume （LVVOLd）， and left ventricular end-systolic volume （LVVOLs） were significantly increased （P<0.01）. The levels of NO and VEGF were significantly decreased （P<0.01）， while the levels of ET-1 and vWF were significantly increased （P<0.01）. Under electron microscopy， the microvascular basement membrane was incomplete and the tight junctions were blurred. The expression levels of ATP5D， F-actin， occludin， claudin， ZO-1， and VE-Cadherin were significantly decreased （P<0.05， P<0.01）， and the relative density of microvessels was significantly reduced （P<0.05， P<0.01）. After intervention with Shengxiantang， the EF and FS of CHF rats significantly increased （P<0.01）， while the LVIDd， LVIDs， LVPWd， LVPWs， LVVOLd， and LVVOLs significantly decreased （P<0.01）. The levels of NO and VEGF significantly increased （P<0.01）， while the levels of ET-1 and vWF significantly decreased （P<0.01）. Under electron microscopy， the microvascular basement membrane was relatively complete and the tight junctions were more continuous. The expression levels of ATP5D， F-actin， occludin， claudin， ZO-1， and VE-Cadherin significantly increased （P<0.05， P<0.01）， and the relative density of microvessels significantly increased （P<0.01）. ConclusionShengxiantang can effectively improve the cardiac function of CHF rats， reduce microvascular endothelial injury， strengthen the connection between endothelial cells， and increase microvessel density， thereby protecting myocardial microvascular injury.

Objective:To investigate the clinical manifestations of medically refractory hereditary movement disorders in children and the efficacy of deep brain stimulation (DBS).Methods:A case series study.The clinical and follow-up data of 20 children with medically refractory hereditary movement disorders who underwent DBS treatment at the Neurology and Functional Neurosurgery Departments of Beijing Children′s Hospital, Capital Medical University, from July 2018 to April 2024, were retrospectively analyzed.The severity of movement disorder symptoms and surgical effects were evaluated using the Burke-Fahn-Marsden Dystonia Rating Scale Movement(BFMDRS-M) or the Unified Parkinson′s Disease Rating Scale Ⅲ(UPDRS Ⅲ).Results:There were 12 males and 8 females among the 20 children, with an onset age ranging from 4 months to 12 years and 5 months.Fourteen patients had hereditary dystonia, which is related to KMT2B in 11 patients, TOR1A in 2 patients and SGCE in 1 patient.Two patients had choreoathetosis, which is related to ADCY5-related familial movement disorders.Two patients had early-onset Parkinson′s disease, which is related to ATP6AP2 in 1 patient and VPS13C in 1 patient.Two patients had neurodevelopmental disorders with involuntary movements, which is related to GNAO1 in 1 patient, and the other patient was idiopathic.All the children were given oral Levodopa, Benzhexol, Baclofen, Tiapride Hydrochloride, Clonazepam alone or in combination.Three children showed obvious dyskinesia after Levodopa treatment.The symptoms of movement disorders in all children exhibited little to no improvement.Levetiracetam and Zonisamide had unstable effects in the treatment of myoclonia.DBS surgery was performed on all the patients aged from 3 to 16 years.Electrodes were successfully inserted into bilateral globus pallidus internus in 14 cases and bilateral subthalamic nuclei in 4 cases.The target was unknown in 2 cases.No surgery-related complications were observed.The patients were followed up for 3 months to 6 years, and the last follow-up age of the patients ranged from 5 years and 7 months to 22 years and 1 month.The rate of improvement in BFMDRS-M score was 37%-100% in 16 patients and >70% in 7 patients with hereditary dystonia.The rate of improvement in UPDRS Ⅲ score was 23% in 1 patient with VPS13C-related early-onset Parkinson′s disease. Conclusions:Childhood medically refractory hereditary movement disorders are a case series that exhibits significant phenotypic and genotypic heterogeneity.DBS surgery demonstrates significant efficacy for KMT2B-, TOR1A-, and SGCE-related hereditary movement disorders.

To summarize the problems and improvement suggestions in the implementation of GBZ158, the focus groups interview was used to interview industry experts from CDC, Occupational disease prevention and control hospital institutes, employers, third d dd鄄party technical service institutions and universities, and extract their opinions on the problems and improvement suggestions in the implementation of the standard. The operability of GBZ 158 is not strong, and there is a certain overlap with the signs in the fields of firefighting, safety and other fields. It urgently needs to be modified to comply with the reality of occupational health management in China. There are many and concentrated revision opinions on "6. Notification Cards for Occupational Hazards of Toxic Substance in Workplaces" and "7. Setting of Warning Signs in Workplaces with Toxic Substances". It is concluded that Some technical indicators of GBZ 158 have not been according with the current actual work of occupational health, and need to be revised and improved urgently, which includes enhancing the coordination with standards in the fields of firefighting and safety, supplementing normative reference documents, clarifying the setting conditions, scope of use, and application examples of warning signs of occupational hazards.

Objective:To investigate the impact of chromate exposure on pulmonary function indices in occupational populations and explore the potential role of alterations in inflammatory indicators in this process.Methods:In July 2024, A cross-sectional analysis was conducted using occupational health examination data of 30875 workers from chromate-related enterprises in Jiangsu Province in 2020 and 2021. Based on the occupational positions and whether there is chromium acid salt exposure in the occupational hazards of the research subjects over the years, they are divided into chromium acid salt exposure group and non-exposure group. For those exposed to chromium acid salts, based on job position descriptions and duration of chromium acid salt exposure, they are further categorized into intermittent exposure group and continuous exposure group; among them, the actual exposure time in the intermittent exposure group is less than half of the working shift time, and the exposure duration is less than the total working life. Pulmonary function test indicators include forced vital capacity (forced vital capacity, FVC) %, first-second forced expiratory volume (forced expiratory volume in one second, FEV 1.0) %, and the ratio of first-second forced expiratory volume to forced vital capacity (FEV 1.0/FVC) %. Peripheral blood samples from the upper limbs of the research subjects were collected on an empty stomach for routine blood tests, selecting neutrophil count, platelet count, and lymphocyte count results, calculating the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). Quantitative data that meet normal distribution are expressed using Mean±SD, while variables that do not meet normal distribution are represented by M ( Q1, Q3). Categorical data are expressed using frequency or proportion (%). Linear variable comparisons between groups use t-tests. Generalized linear models were employed to assess the correlation between chromate exposure and pulmonary function indices, while mixed regression models were utilized to explore potential underlying effects. Results:Compared with the non-exposed group, the pulmonary function indices FVC (%), FEV 1.0/FVC (%), and FEV 1.0 (%) in the chromate-exposed group showed a decreasing trend ( P<0.01), indicating statistically significant differences. As the frequency of chromate exposure increased, the prevalence of pulmonary dysfunction rose. The prevalence rates of obstructive, restrictive, and mixed respiratory dysfunction among the chromate-exposed population (including intermittent exposure and continuous exposure groups) were 0.26%, 4.67%, and 0.12%, which were higher than those in the non-exposed group (0.09%, 0.84%, and 0.07%, respectively). All these differences were statistically significant ( P<0.05). After stratification by gender, a negative correlation was observed between chromate exposure and the inflammatory indicator platelet-to-lymphocyte ratio (PLR) ( P<0.05). Potential effect analysis revealed that PLR played a certain mediating role between chromate exposure and the decline in pulmonary function indices, with a mediating proportion of 2.2%. Conclusion:Chromate exposure in occupational populations may lead to a decline in pulmonary ventilatory function and alterations in peripheral blood inflammatory indicators. Inflammatory indicators may be involved in the pulmonary function decline caused by chromate exposure.

Objective:To study and compare the occupational exposure limits (OELs) of nickle and its compounds between China and foreign countries, providing scientific basis for the OEL revision of nickel and its compounds in China.Methods:From July to September 2024, Literature, OEL and related technical documents on nickel and its compounds were searched and sorted systematically at home and abroad, the main contents and technical points of OEL were extracted, and comparative analysis were conducted.Results:The earliest OELs of nickel and its compound introduced to China was maximum allowable concentration (MAC) of nickel carbonyl, and the current effective standard China was occupational exposure limits for hazardous agents in the workplace-part 1: chemical hazardous agents (GBZ 2.1-2019), covering nickel and inorganic compounds and nickel carbonyl. The former was further divided into nickel metal and insoluble compounds, and soluble nickel compounds. Based solely on the OELs of nickel and its compounds, China was relatively lower compared to developed countries such as the United States. There were significant differences in the OEL of different types of nickel and its compounds among different countries, but the OELs in China and the United Kingdom (UK) Health and Safety Executive (HSE) were basically consistent. The European Union, the United States American Conference of Governmental Industrial Hygienists (ACGIH), South Africa etal classified nickel and its compounds into respirable and inhalable based on particle size. GBZ 2.1-2019 in China labeled nickel compounds and nickel carbonyl as G1 (carcinogenic to humans), while ACGIH and National Institute for Occupational Safety and Health (NIOSH) in the United States, HSE in the UK, Australia, South Africa also labeled one or several different types of nickel and its compounds as carcinogenic.Conclusion:Based on the OELs of nickel and its compounds, China is at a relatively loose level. It is suggested to explore the possibility of future revision, considering various adverse health effects. It is suggested to conduct basic research on fibrosis induced by nickel and its compounds, providing scientific basis for revising OELs.