The Impact of Comprehensive Nursing and Warming Measures on Emergence Agitation and Maternal-Neonatal Safety in Women Undergoing General Anesthesia for Cesarean Section.

Objective: To explore the effects of comprehensive nursing combined with thermal insulation measures on the awakening agitation (EA) of cesarean section parturient under general anesthesia and maternal and infant safety. Methods: A total of 136 cesarean section parturients under general anesthesia admitted in our hospital from May 2020 to November 2023 were picked as the research objects following the random, double-blind method. All patients have no mental illness and can clearly reflect their physical state. The subjects were randomized into the study group and the control group in accordance with the random number table method, with 68 cases in each group. The control group was intervened with thermal insulation measures, while the study group was intervened with comprehensive nursing combined with thermal insulation measures. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) at different time points were compared. The Ramsay score (RASS), the incidence of EA, and the incidence of shivering were compared. The influence of comprehensive nursing combined with thermal insulation measures on maternal and infant safety and their recovery after the operation was analyzed. The adverse psychological status and postoperative satisfaction of the two groups were statistically analyzed. Results: SBP, DBP, and MAP in the study group were much higher than those in the control group at the time of skin incision, fetal delivery, and the end of operation (P < .05). Compared with the control group, the study group had much higher RASS, and sharply reduced incidence of EA and shivering (P < .05). The incidence of fetal distress, postpartum hemorrhage, neonatal asphyxia, etc., was significantly lower in the study group than in the control group P < .05). Parturient of the study group had a shorter duration of hospitalization, shorter detention time in the anesthesia monitoring room, and awakening time than the parturient in the control group (P < .05). The SAS and SDS scores of parturient were significantly decreased in the two groups at discharge than before the operation, and a more obvious decrease was found in the study group (P < .01). Postoperative satisfaction of the study group and the control group was 98.53% and 80.88%, respectively, which was markedly higher in the study group than in the control group (P < .05). Conclusion: Comprehensive nursing combined with thermal insulation measures vastly improved the sedation degree of parturient, reduced the incidence of EA and chills, ensured maternal and infant safety, reduced adverse pregnancy outcomes, promoted early recovery of parturient, and enhanced maternal satisfaction. This conclusion provides important guidance for improving clinical practice, emphasizing the key role of comprehensive care in improving surgical outcomes and patient comfort, thereby improving the quality and efficiency of medical services.

Uniform Lithium Plating for Dendrite-Free Lithium Metal Batteries: Role of Dipolar Channels in Poly(vinylidene fluoride) and PbZrxTi1-xO3 Interface.

Conventional polymer/ceramic composite solid-state electrolytes (CPEs) have limitations in inhibiting lithium dendrite growth and fail to meet the contradictory requirements of anodes and cathodes. Herein, an asymmetrical poly(vinylidene fluoride) (PVDF)-PbZrxTi1-xO3 (PZT) CPE was prepared. The CPE incorporates high dielectric PZT nanoparticles, which enrich a dense thin layer on the anode side, making their dipole ends strongly electronegative. This attracts lithium ions (Li+) at the PVDF-PZT interface to transport through dipolar channels and promotes the dissociation of lithium salts into free Li+. Consequently, the CPE enables homogeneous lithium plating and suppresses dendrite growth. Meanwhile, the PVDF-enriched region at the cathode side ensures intermediate contact with positive active materials. Therefore, Li/PVDF-PZT CPE/Li symmetrical cells exhibit a stable cycling performance exceeding 1900 h at 0.1 mA cm-2 at 25 °C, outperforming Li/PVDF solid-state electrolyte/Li cells that fail after 120 h. The LiNi0.8Co0.1Mo0.1O2/PVDF-PZT CPE/Li cells show low interfacial impedances and maintain stable cycling performance for 500 cycles with a capacity retention of 86.2% at 0.5 C and 25 °C. This study introduces a strategy utilizing dielectric ceramics to construct dipolar channels, providing a uniform Li+ transport mechanism and inhibiting dendrite growth.

Active compounds and potential targets of Shuganning injection in the treatment of hepatocellular carcinoma by network pharmacology and in vitro validation.

Shuganning injection (SGNI), a TCM (traditional Chinese medicine) injection with good hepatoprotective effects, exerted therapeutic effects on hepatocellular carcinoma (HCC). However, the active compounds and effects of SGNI on HCC remain unclear. The objective of this study was to investigate the active compounds and potential targets of SGNI in the treatment of HCC, and explore the molecular mechanisms of main compounds. Network pharmacology was applied to predict the active compounds and targets of SGNI on cancer. The interactions between active compounds and target proteins were validated by drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA), and pull-down assay. The in vitro test of the effects and mechanism of vanillin and baicalein was elucidated by MTT, western blot, immunofluorescence, and apoptosis analysis. According to compound characteristics, targets, etc., two typical active ingredients (vanillin and baicalein) were selected as representatives to explore the effects on HCC. Vanillin (an important food additive) bound to NF-κB1 and baicalein (a bioactive flavonoid) bound to FLT3 (FMS-like tyrosine kinase 3) were confirmed in this study. Vanillin and baicalein both inhibited cell viability and promoted apoptosis of Hep3B and Huh7 cells. In addition, both vanillin and baicalein could enhance the activation of the p38/MAPK (mitogen-activated protein kinase) signaling pathway, which may partially explain the anti-apoptosis effects of the two compounds. In conclusion, two active compounds of SGNI, vanillin and baicalein, promoted apoptosis of HCC cells via binding with NF-κB1 or FLT3, and regulating the p38/MAPK pathway. Baicalein and vanillin may be good candidates for HCC treatment on drug development.

Polyphenols as potential metabolism mechanisms regulators in liver protection and liver cancer prevention.

BACKGROUND: Liver cancer is one of the common malignancies. The dysregulation of metabolism is a driver of accelerated tumourigenesis. Metabolic changes are well documented to maintain tumour growth, proliferation and survival. Recently, a variety of polyphenols have been shown to have a crucial role both in liver disease prevention and metabolism regulation. METHODS: We conducted a literature search and combined recent data with systematic analysis to comprehensively describe the molecular mechanisms that link polyphenols to metabolic regulation and their contribution in liver protection and liver cancer prevention. RESULTS: Targeting metabolic dysregulation in organisms prevents and resists the development of liver cancer, which has important implications for identifying new therapeutic strategies for the management and treatment of cancer. Polyphenols are a class of complex compounds composed of multiple phenolic hydroxyl groups and are the main active ingredients of many natural plants. They mediate a broad spectrum of biological and pharmacological functions containing complex lipid metabolism, glucose metabolism, iron metabolism, intestinal flora imbalance, as well as the direct interaction of their metabolites with key cell-signalling proteins. A large number of studies have found that polyphenols affect the metabolism of organisms by interfering with a variety of intracellular signals, thereby protecting the liver and reducing the risk of liver cancer. CONCLUSION: This review systematically illustrates that various polyphenols, including resveratrol, chlorogenic acid, caffeic acid, dihydromyricetin, quercetin, catechins, curcumin, etc., improve metabolic disorders through direct or indirect pathways to protect the liver and fight liver cancer.

The Application Value of Metagenomic and Whole-Genome Capture Next-Generation Sequencing in the Diagnosis and Epidemiological Analysis of Psittacosis.

Background: To evaluate the value of metagenomic next-generation sequencing (mNGS) for the early diagnosis of psittacosis, and to investigate its epidemiology by whole-genome capture. Methods: Twenty-one bronchoalveolar lavage fluid (BALF) and blood samples of 16 psittacosis patients from multiple centers during August 2019 to September 2021 were analyzed retrospectively. mNGS with normal datasets (10 M 75-bp single-end reads after sequencing) and larger datasets (30 M 150-bp paired-end reads after sequencing) as well as quantitative real-time polymerase chain reaction (qPCR) were used to detect the pathogen. Also, whole-genome capture of Chlamydophila psittaci was applied to draw the phylogenetic tree. Results: mNGS successfully detected the pathogen in all 16 cases (100%), while qPCR was positive only in 5 out of 10 cases (50%), indicating a significantly higher sensitivity of mNGS than qPCR (p < 0.01). BALF-mNGS performed better than blood-mNGS (16/16 versus 3/5, p < 0.05). In addition, larger datasets (the read counts have tripled, and the base number was 12-fold larger compared to clinical mNGS with a normal dataset) of mNGS showed significantly increased contents of human DNA (p < 0.05) and decreased reads per million of the pathogen, suggesting no improvement. Whole-genome capture results of five samples (>60% coverage and >1 depth) were used to construct the phylogenetic tree. Conclusion: Significant advantages of mNGS with normal datasets were demonstrated in early diagnosing psittacosis. It is the first study to use whole-genome capture to analyze C. psittaci epidemiological information.

Long noncoding RNA MIR3142HG accelerates lipopolysaccharide-induced acute lung injury via miR-95-5p/JAK2 axis.

The study aims to clarify the expression pattern of MIR3142HG in acute lung injury (ALI) and investigate the potential mechanisms for the regulatory role of MIR3142HG in JAK/STAT in ALI. Notably, the ALI patients presented the overexpression of MIR3142HG and JAK2 in their serum samples. Knockdown of MIR3142HG facilitated cell viability but impaired cell apoptosis and inflammatory response via targeting miR-95-5p in lipopolysaccharide (LPS)-treated ALI cells. Overexpression of miR-95-5p promoted cell viability but suppressed apoptosis and inflammatory response via targeting JAK2 in LPS-induced ALI cells. The rescue experiments indicated that inhibition of miR-95-5p could reverse the increased cell viability and promote the inhibited apoptosis and inflammatory response induced by MIR3142HG knockdown in LPS-induced ALI. In conclusion, MIR3142HG is increased in sepsis-induced ALI, and MIR3142HG could accelerate the progression of sepsis-induced ALI through miR-95-5p/JAK2 axis, providing theoretical evidence for MIR3142HG to be a promising target for the therapeutics of ALI.

Circular RNA circ_0023404 serves as a miR-636 sponge to promote malignant behaviors in cervical cancer cells through upregulation of CYP2S1.

Cervical cancer is the most common malignant gynecological tumor. Circular RNA (circRNA) circ_0023404 is reported to be upregulated in cervical cancer cells. This aim is to explore the role and mechanism of circ_0023404 in cervical cancer. circ_0023404, microRNA-636 (miR-636), and cytochrome P450 2S1 (CYP2S1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, migration, invasion, and apoptosis were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, 5-ethynyl-2'-deoxyuridine (EDU) assay, colony formation assay, transwell assay, and cytometry assay. Protein levels of cyclin D1, matrix metallopeptidase 9 (MMP9), Bcl-2-associated X protein (Bax), and CYP2S1 were examined by western blot assay. The binding relationship between miR-636 and circ_0023404 or CYP2S1 was predicted by Circinteractome or targetscan, and then verified by a dual-luciferase reporter assay and RNA pull-down assay. circ_0023404 and CYP2S1 expression were increased, and miR-636 was decreased in cervical cancer tissues and cells. Moreover, circ_0023404 knockdown could repress proliferation, migration, invasion, and promote apoptosis of cervical cancer cells in vitro. Mechanically, circ_0023404 could regulate CYP2S1 expression by sponging miR-636. circ_0023404 silencing could attenuate the progression of cervical cancer cells partly by targeting the miR-636/CYP2S1 axis, hinting at a promising therapeutic target for cervical cancer.

Effective Doses of Nalbuphine Combined With Propofol for Painless Gastroscopy in Adults: A Randomized Controlled Trial.

Objective: This prospective study evaluated the 50% effective dose (ED50) and 95% effective dose (ED95) of nalbuphine combined with propofol during painless gastroscopy. Methods: Seventy-five patients who underwent painless gastroscopy were randomly divided into five groups (group N0, N0.05, N0.1, N0.15, and N0.2), with doses of 0, 0.05, 0.1, 0.15, or 0.2 mg/kg nalbuphine in each group. Propofol was given to all groups as the sedative. The bispectral index (BIS) value, propofol dose, examination time, and awakening time were recorded. The number of patients with intolerance indexes (coughing, retching, swallowing, or limb movement) was recorded in each group. The ED50/ED95 of nalbuphine combined with propofol for gastroscopy were calculated. Results: Compared with those of groups N0, N0.05, or N0.1, the propofol dose and awakening time were significantly reduced in group N0.15 or N0.2 (p < 0.05). The successful rate of painless gastroscopy in group N0.15 or N0.2 significantly increased compared to that of group N0 or N0.05 (p < 0.05). When combined with propofol, nalbuphine had an ED50 and ED95 for painless gastroscopy of 0.078 mg/kg (95% CI, 0.056-0.098 mg/kg) and 0.162 mg/kg (95% CI, 0.134-0.217 mg/kg), respectively. Conclusion: The ED50/ED95 of nalbuphine combined with propofol are 0.078 and 0.162 mg/kg, respectively, for painless gastroscopy. Nalbuphine at 0.162 mg/kg combined with propofol is effective and safe for painless gastroscopy in adults.

Dexmedetomidine targets miR-146a and participates in the progress of chronic obstructive pulmonary disease in vivo and in vitro.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a chronic lung disease and the third leading cause of death in the world. Dexmedetomidine has been reported to effectively inhibit histamine-induced bronchoconstriction. However, the molecular mechanism of dexmedetomidine in COPD has not been found. OBJECTIVE: To explore the role and mechanism of dexmedetomidine in COPD, and to provide theoretical basis for clinical treatment of COPD. METHODS: The expression of miR-146a was regulated by mimics or inhibitor and the relative expression of apoptotic proteins p53, Bax and Bcl-2 in human bronchial epithelial 16HBE cells was determined by real-time PCR and Western blot. Dexmedetomidine was treated for 16HBE cells and alveolar epithelial type II cells (AEC2), the cell apoptosis was detected by TUNEL and Hoechst33342 staining. A COPD rat model was established by smoking to test the effects of dexmedetomidine on the progression of COPD. The levels of IL-6, IL-1ß and TNF-α in serum were measured by ELISA and the protein concentration of bronchoalveolar lavage fluid (BALF) was also detected in dexmedetomidine treated COPD rat model. RESULTS: miR-146a promoted 16HBE cell apoptosis and reduced cell proliferation. Additionally, dexmedetomidine was showed to reduce the 16HBEL cell apoptosis through reducing the expression of miR-146a. Moreover, dexmedetomidine regulated cell apoptosis and cell apoptosis through miR-146a in AEC2 cells. More importantly, dexmedetomidine attenuated the morphology and pathology of COPD rat model. CONCLUSION: Dexmedetomidine reduced 16HBE cells and AEC2 cell apoptosis and attenuated COPD by down-regulating miR-146a.

Effects of dexmedetomidine on cognitive function in elderly patients after laparoscopic cholecystectomy: A protocol for systematic review and meta-analysis.

BACKGROUND: Although many studies have reported the effects of dexmedetomidine on cognitive function (CF) in elderly patients after laparoscopic cholecystectomy (LCT), to this date, its effects are still not well understood. The aim of this study is to produce a qualitative synthesis of assessing the effects of dexmedetomidine on CF in elderly patients after LCT. METHODS: We will conduct a comprehensive search in Cochrane Library, MEDLINE, EMBASE, CINAHL, PsycINFO, Scopus, VIP Database, WANGFANG Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure from the commencement to March 31, 2020 without restrictions of language and publication status. In addition, we will also search grey literature, including conference abstracts, dissertations, reference lists of included studies and relevant reviews. All potential studies will be identified independently by 2 authors to determine their inclusion against previously defined eligibility criteria. The quality of selected papers will be assessed using Cochrane risk of bias tool. All statistical analysis will be performed using RevMan 5.3 software. RESULTS: This study will provide a synthesis of the current available data on assessing the effects of dexmedetomidine on CF in elderly patients after LCT. CONCLUSIONS: Its findings will provide qualitative evidence to better understand the effects of dexmedetomidine on CF in elderly patients after LCT.INPLASY Registration Number: INPLASY202040030.

Analgesic effect of AG490, a Janus kinase inhibitor, on oxaliplatin-induced acute neuropathic pain.

Neuropathic pain often occurs during chemotherapy with oxaliplatin. AG490 has been shown to exert an antagonistic effect on inflammatory pain, but its effect on oxaliplatin-induced neuropathic pain remains poorly understood. This study sought to observe the analgesic effect of AG490 on acute neuropathic pain induced by a single oxaliplatin treatment and to address the possible mechanism. In this study, we established a model of oxaliplatin-induced acute neuropathic pain by intraperitoneal injection of 6 mg/kg oxaliplatin. On day 2 after injection, models were intraperitoneally injected with 1, 5, or 10 mg/kg AG490. Paw withdrawal threshold to mechanical stimuli and tail withdrawal latency to cold stimuli were determined. Western blot assay was performed to detect the expression of spinal phosphorylated signal transducer and activator of transcription 3 (p-STAT3). Immunohistochemistry was used to determine the immunoreactivity of p-STAT3 and interleukin-6. Results demonstrated that paw withdrawal threshold and tail withdrawal latency were significantly increased by the treatment of AG490 in rats. There was no significant difference in the effect among the different doses of AG490. AG490 10 mg/kg decreased the expression of p-STAT3, the immunoreactivity of p-STAT3 and interleukin-6 in spinal cord of acute neuropathic pain rats. These findings confirm that AG490 can attenuate oxaliplatin-induced acute neuropathic pain and is associated with the inhibition in the JAK/STAT3 signaling pathway.

[Analgesic effect of dexmedetomidine on oxaliplatin-induced neuropathic pain in rats].

OBJECTIVE: To investigate the analgesic effect of dexmedetomidine (Dex) on oxaliplatin-induced neuropathic pain in rats and explore its mechanism. METHODS: SD rats were randomly divided into control, model, Dextreatment, and Dex + atipamezole groups. In the latter 3 groups, rat models of neuropathic pain were established by a single intraperitoneal injection of oxaliplatin. The paw withdrawal threshold (PWT) to mechanical stimuli and tail withdrawal latency (TWL) to thermal stimuli of the rats were determined. Western blotting and immunofluorescence assay were performed to observe the expression of spinal phosphorylated STAT3 (p-STAT3) in the rats. RESULTS: Compared with the rats in the control group, the rats in the model group and Dex+atipamezole group showed significantly decreased PWT and TWL (cold) and increased expression of p-STAT3 in the spinal cord (P < 0.05). In Dex group, PWT and TWL (cold) were significantly increased (P < 0.05) and p-STAT3 expression in the spinal cord was significantly decreased (P < 0.01) 60 to 120 after Dex treatment as compared with those in the model group, and these effects of Dex were significantly attenuated by the administration of atipamezole (P < 0.05). CONCLUSIONS: Dex can alleviate oxaliplatin-induced neuropathic pain in rats by inhibiting the phosphorylation of STAT3 in the spinal cord.

[Effects of hydrogen sulfide preconditioning on myocardial ischemia reperfusion injury in rats].

OBJECTIVE: To investigate the effects of hydrogen sulfide preconditioning on myocardial ischemia reperfusion injury in rats. METHODS: Sprague-Dawley male rats were divided into 4 groups with 10 in each group: in S group rats received sham operation; in IR group rats were given with NS (1.0 ml/kg iv) 24 h before ischemia; in H group rats were treated with NaHS (0.05 mg/kg iv) 24 h before ischemia; and in D group, NaHS-treated rats received 5-hydroxydecanoate (5-HD) 15 min before ischemia. Rats in IR group,H group and D group were subjected to ischemia by occlusion of coronary artery for 30 min followed by 2 h of reperfusion. At the end of the reperfusion,myocardial infarct size was measured. SAM-s was measured by Western blotting. Plasma SOD activity and MDA were determined at the end of reperfusion. RESULTS: The infarct size was significantly lesser in H group (25.40 % ± 3.54%) than that in IR group (38.27% ±5.64%,P<0.05). The SAM-s protein expression in myocardium was significantly lower in H group than that in IR group. The plasma MDA content was significantly lower and SOD activity was higher in H group than those in IR group,but there was no difference between IR group and D group. CONCLUSION: The hydrogen sulfide preconditioning attenuates myocardial IR injury possibly through down-regulating SAM-s expression,reducing the production of oxygen free radicals and enhancing anti-oxidize effect in rats.

[Detecting the isoflurane in the air of workplaces with chromatographic method].

OBJECTIVE: To establish a solvent desorption Gas chromatographic method for detecting the isoflurane in air of workplaces. METHODS: This method is based on "Standardization of methods for determination of toxic substances in workplace air". RESULTS: This method presents the linear relation with the minimum detectable limit 1.0 µg/ml and the minimum detectable concentration 0.07 mg/m(3). The precision (RSD) was 0.5% ∼ 5.0%, the mean dsorption efficiencies were 96.7% ∼ 98.9%, the absorption efficiencies were 92.1% ∼ 100%, the breakthrough volume was 3.7 mg isoflurane/100 mg active carbon. Other volatile organic solvents (Sevoflurane, Enflurane and Ethyl Alcohol) did not interfere the detection. The sample could be stored in the active carbon tube at least for 10 days. CONCLUSION: This method is meet the requirement of GBZ/T 210.4-2008 "Guide for establishing occupational health standards-Part4: Determination methods of air chemicals in workplace" and is feasible for determining the isoflurane in the air of workplaces.

[Effect of hydrogen sulfide-induced delayed preconditioning on glutathione S-transferase expression during myocardial ischemia-reperfusion in rats].

OBJECTIVE: To investigate the effect of hydrogen sulfide-induced delayed preconditioning on glutathione S-transferase (GST) expression during myocardial ischemia-reperfusion in rats. METHODS: Sprague-Dawley male rats were randomly divided into 4 groups (n= 10 in each): Group S (sham operation group), Group IR (ischemia/reperfusion group), Group H (IR+ NaHS 0.05 mg/kg iv, 24 h before ischemia) and Groups D receiving IR+NaHS 24 h before ischemia and 5-hydroxydecanoate (5-HD)15 min before ischemia. Animals in groups IR, H and D were subjected to ischemia by 30 min of coronary artery occlusion followed by 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size (IS) was examined. Glutathione S-transferase (GST) was measured by Western blotting. The myocardial ultrastructures were observed under the electron microscopy. RESULTS: The IS was significantly smaller in Group H than that in Group IR [(25.40 ± 3.54)% compared with (38.27 ± 5.64)%, P<0.05]. The GST expression in myocardium was significantly higher in Group H than that in Group IR. Microscopic examination showed less myocardial damage in Group H than in Group IR. The protective effects of delayed preconditioning by hydrogen sulfide was prevented by 5-HD pre-treatment. CONCLUSION: The hydrogen sulfide-induced delayed preconditioning attenuates myocardial IR injury possibly through up-regulating glutathione S-transferase expression in rats.

[Determination of phosphoric acid in the air of workplace by ion chromatography].

OBJECTIVE: To develop a method to determine phosphoric acid in the air of workplace by ion chromatography. METHODS: Phosphoric acid was collected by millipore filter and washed by deionized water then detected by ion chromatography. RESULTS: Linearity range of test was 0 ∼ 20 µg/ml, relative standard deviation (RSD) was 1.95% ∼ 3.31%, the elution efficiency was 103.0% ∼ 109.6%, determination limit was 0.1 µg/ml (when sample size was 20.01) concentration limit was 0.01 mg/m(3) (when the collected air was 75 L). CONCLUSION: This method is convenient for air collection, simple, with high sensitivity and good precision, is a good method for determination of phosphoric acid in the air of workplace.

[Simultaneous determination of seven chemicals of halogenated alkanes and aromatic hydrocarbons in the air of workplace by gas chromatography].

OBJECTIVE: To establish a gas chromatographic method for determination of halogenated alkanes and aromatic hydrocarbons including trichloromethane, 1,2-dichloroethane, carbon tetrachloride, benzene, toluene, ethylbenzene and xylene in the air of workplace. METHODS: After the air samples collected with activated carbon tubes and desorbed with CS(2), the target toxicants were separated with FFAP capillary columns and detected with flame ionization detector. RESULTS: The coefficient of correlation was above 0.999 and the lowest detectable concentrations were 0.2 ∼ 3.6 mg/m(3) with the RSD of 1.2% ∼ 4.6%. The desorption efficiencies was 94.9% ∼ 100.7%. CONCLUSION: The method shows lower detection limit, high accuracy and precision. It is feasible for determination of the seven halogenated alkanes and aromatic hydrocarbons in the air of workplace.