Amides can be obtained in good to excellent yield by Sm/TiCl(4) mediated reductive cleavage of N=N bond in azo compounds and successive acylation in one pot. It offers an alternative method for the synthesis of amides from very simple starting materials directly.
Azo Compounds ; chemistry ; Chlorine Compounds ; chemistry ; Combinatorial Chemistry Techniques ; methods ; Halogens ; chemistry ; Samarium ; chemistry ; Titanium ; chemistry

OBJECTIVESince haloacetic acids (HAAs), which are nonvolatile and of high carcinogenic risk, are common species of chlorinated disinfection by-products(DBPs) in drinking water, and little has been known in China, it is necessary to make a survey about the kinds and levels of HAAs in drinking water of the nation.

METHODHAAs were analyzed using gas chromatography with electron capture detector(GC/ECD) and relatively complex pretreatment process of sample was applied. Five main cities in different areas of China were chosen in the survey.

RESULTSStudies showed that the main species of HAAs in drinking water in China were DCAA and TCAA, ranging from 0.4 microg/L to 12.85 microg/L and from 0.56 microg/L to 10.98 microg/L, respectively. MBAA and DBAA were also detected in one city, ranging from 2.20 microg/L to 4.95 microg/L and 1.10 microg/L to 2.81 microg/L, respectively. Therefore, the contents of HAAs varied, usually no more than 25 microg/L. Based on the acquired data to date, it is known that the concentrations of HAAs in drinking water in China were surely under the limits of Sanitary Standard for Drinking Water Quality (China, 2001).

CONCLUSIONA wider survey of HAAs in drinking water should be conducted throughout the nation to get adequate data and information, the ultimate aim of which is to control HAAs pollution and keep the balance between microbiological safety insurance and chemical risk control, minimize the formation of DBPs and ensure the safety of water supply at the same time.

Acetates ; analysis ; China ; Chlorine ; chemistry ; Cities ; Environmental Monitoring ; Halogens ; chemistry ; Humans ; Seasons ; Water Purification ; Water Supply

ObjectiveExposure to halogens, such as chlorine or bromine, results in environmental and occupational hazard to the lung and other organs. Chlorine is highly toxic by inhalation, leading to dyspnea, hypoxemia, airway obstruction, pneumonitis, pulmonary edema, and acute respiratory distress syndrome (ARDS). Although bromine is less reactive and oxidative than chlorine, inhalation also results in bronchospasm, airway hyperresponsiveness, ARDS, and even death. Both halogens have been shown to damage the systemic circulation and result in cardiac injury as well. There is no specific antidote for these injuries since the mechanisms are largely unknown.

Data SourcesThis review was based on articles published in PubMed databases up to January, 2018, with the following keywords: "chlorine," "bromine," "lung injury," and "ARDS."

Study SelectionThe original articles and reviews including the topics were the primary references.

ResultsBased on animal studies, it is found that inhaled chlorine will form chlorine-derived oxidative products that mediate postexposure toxicity; thus, potential treatments will target the oxidative stress and inflammation induced by chlorine. Antioxidants, cAMP-elevating agents, anti-inflammatory agents, nitric oxide-modulating agents, and high-molecular-weight hyaluronan have shown promising effects in treating acute chlorine injury. Elevated free heme level is involved in acute lung injury caused by bromine inhalation. Hemopexin, a heme-scavenging protein, when administered postexposure, decreases lung injury and improves survival.

ConclusionsAt present, there is an urgent need for additional research to develop specific therapies that target the basic mechanisms by which halogens damage the lungs and systemic organs.

Acute Lung Injury ; chemically induced ; Animals ; Chlorine ; toxicity ; Halogens ; toxicity ; Humans ; Lung ; drug effects ; pathology ; Respiratory Distress Syndrome, Adult ; drug therapy

OBJECTIVESTo investigate the power density and other relevant data of clinical curing-light units used in Changchun, and to provide practice recommendations to clinical dentists about maintaining of cuing-light units.

METHODSStomatology hospitals, departments of stomatology in general hospitals, and private dental offices in Changchun were randomly selected to participate in the Survey. The investigation analyzed 270 curing-light units. The following data of curing-light units were gathered: brand, type, operation ages, numbers and types of light guide, resin build-ups on light guides, damages of light guides, use frequency, monitor and maintenance of curing lights, and unit numbers/chair numbers.

RESULTSThere were 174 QTH and 96 LED units. The distribution of power density was from 0 to 1702 mW/cm(2). The mean power density was 413.2 mW/cm(2). The power densities of 73 lights were less than 200 mW/cm(2) and could not polymerize resin composites adequately. The mean number of operation age of the light units was 4.74 years. Most of clinical dentists didn't monitor the light-curing units and the situation of build-up from composite resin or damages on light guides was very severe.

CONCLUSIONSMost of the light-curing units used in Changchun were QTH. Some QTH units degenerate severely and need to be replaced with the new ones. Most of the clinical doctors lack the knowledge of how to properly monitor and maintain the light-curing units.

China ; Composite Resins ; chemistry ; Curing Lights, Dental ; classification ; statistics & numerical data ; Halogens ; Quartz ; Semiconductors ; Tungsten

OBJECTIVETo measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals.

METHODSThe concentration values causing 50% inhibition of bacteria growth (24h-IC50) were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program.

RESULTSThe log1/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters: log1/IC50 = -0.531(E(LUMO)) + 1.693(Qc) + 0.163(logP) + 3.375. This equation was found to fit well (r2 = 0.860, s = 0.106), and the average percentage error was only 1.98%.

CONCLUSIONHalogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group.

Aliivibrio fischeri ; drug effects ; Benzene ; chemistry ; toxicity ; Halogens ; chemistry ; Quantitative Structure-Activity Relationship ; Rivers ; chemistry ; microbiology ; Toxicity Tests, Acute ; Water Pollutants, Chemical ; chemistry ; toxicity

No abstract available.
Iodine*

OBJECTIVETo study the interaction of fluorine (F), calcium (Ca) and iodine (I) on body weight of rats.

METHODSOne-month-old Wistar rats were randomly divided into 8 groups: moderate concentrations of F, Ca, I (group 1); moderate concentrations of F, I and high concentration of Ca (group 2); moderate concentrations of Ca, I and high concentration of F (group 3); moderate concentration of I and high concentrations of F, Ca (group 4); moderate concentrations of F, Ca and low concentration of I (group 5); moderate concentration of F,high concentration of Ca and low concentration of I (group 6); moderate concentration of Ca, high concentration of F and low concentration of I (group 7); high concentrations of F, Ca and low concentration of I (group 8) based on 2 x 2 x 2 factorial design. The moderate concentration of F was 90 microg/d and the high concentration of F was 2700 microg/d. The moderate Ca concentration was 13 mg/d and the high Ca concentration was 260 mg/d. The moderate concentration of I was 3.5 microg/d and the low concentration of I was 0.23 microg/d. After twenty weeks, body weight was measured.

RESULTSAccording to the results of factorial ANOVA, significant interaction effects of F with Ca were found (F = 5.933, P = 0.017). The empty body weight was measured at the end of the fifth month. When both iodine and fluorine were at the optimal level, the weight of group 2 [(262.5 +/- 47.1) g] and group 1 [(307.9 +/- 55.0) g] showed significant difference (t = 4.24, P < 0.05). When both iodine and fluorine were at low level, the weight of group 6 [(248.8 +/- 30.0) g] and group 5 [(293.3 +/- 19.7) g] showed significant difference (t = 4.16, P < 0.05). Animals with optimal iodine and calcium [(269.3 +/- 27.3) g] showed significant difference compared to the weight of low level iodine and optimal fluorine [(307.9 +/- 55.0) g]. When the low level iodine and optimal calcium were applied, weight of group 7 [(261.9 +/- 31.3) g] and group 5 [(293.3 +/- 19.7) g] showed significant difference. (t = 2.94, P < 0.05).

CONCLUSIONInteraction effects of F with Ca were found on body weight in rats.

Animals ; Body Weight ; drug effects ; Calcium, Dietary ; pharmacology ; Drug Interactions ; Female ; Fluorides ; Fluorine ; pharmacology ; Iodine ; pharmacology ; Male ; Rats ; Rats, Wistar

It is necessary to use the iodine containing salt and preparation for disease prevention and control. However, we should not forget or consider the adverse effects of iodine containing salt and preparation in case of overdose. It should know the adverse effects of iodine containing salt and preparation and implement correctly the physician's indication to limit and control these adverse effects
Iodine ; Iodine Isotopes ; Overdose

The results of a retrospective study of epidemiological surveys was conducted by National Iodine Deficiency Disorder Control Program and periodic surveys were conducted by the Centre of Preventive Health of An Giang in 1998, 2000 and 2003, showed that the coverage rate of households consumed salt with an iodine concentration of more than 20ppm was 29%, 52.9% and 76.5%, respectively. The median urinary iodine concentration was 1.8mlg/dl, 4.4mg/dl and 5.7mg/dl, respectively. The prevalence of goiter in children age 8-10 years was 20.5%, 12.8% and 6.1%, respectively. In 2003, there were still 71.5% of households situated in the iodine deficiency area in An Giang province. The main reasons make people have not used iodised salt are habit of using normal salt; iodised salt is not available and affordable. Although knowledge about the benefit of iodised salt for preventing endemic goiter is 89.4%, knowledge of using iodised salt for preventing creatinism is low (40%).
Iodine ; Iodine/deficiency ; Epidemiology

No abstract available.
Iodine* ; Psoriasis*