Radiation effects in the forest ecosystems: Acute irradiation.

The paper comprehensively brings together key data on radiation effects observed in the Russian studies with an acute forest irradiation. The experiments were based on the ecosystem approach, including an assessment of the radiation impacts based on a variety of the endpoints. The effects at the cellular level were observed at the lowest doses: a double increase of the chromosome aberrations in the apical meristem of pine were found at the site with the absorbed dose of 2.5 Gy. The effects at the tissues levels and trees mortality expressed in D50 were revealed for the trees received 20-50 Gy and a double reduction in a net primary radioactivity was observed at the doses of 14-38 Gy for pine and 280-750 Gy for birch. The seasonal differences in radiosensitivity of the forest ecosystems were noted: the radiosensitivity of the irradiated trees was 3-5 fold higher after the spring irradiation than that after autumn irradiation. An importance of the ecosystem endpoints is emphasized.

Controlling cyclization pathways in palladium(ii)-catalyzed intramolecular alkene hydro-functionalization via substrate directivity.

We report a series of palladium(ii)-catalyzed, intramolecular alkene hydrofunctionalization reactions with carbon, nitrogen, and oxygen nucleophiles to form five- and six-membered carbo- and heterocycles. In these reactions, the presence of a proximal bidentate directing group controls the cyclization pathway, dictating the ring size that is generated, even in cases that are disfavored based on Baldwin's rules and in cases where there is an inherent preference for an alternative pathway. DFT studies shed light on the origins of pathway selectivity in these processes.

Gene-environment interaction impacts on heart development and embryo survival.

Congenital heart disease (CHD) is the most common type of birth defect. In recent years, research has focussed on identifying the genetic causes of CHD. However, only a minority of CHD cases can be attributed to single gene mutations. In addition, studies have identified different environmental stressors that promote CHD, but the additive effect of genetic susceptibility and environmental factors is poorly understood. In this context, we have investigated the effects of short-term gestational hypoxia on mouse embryos genetically predisposed to heart defects. Exposure of mouse embryos heterozygous for Tbx1 or Fgfr1/Fgfr2 to hypoxia in utero increased the incidence and severity of heart defects while Nkx2-5+/- embryos died within 2 days of hypoxic exposure. We identified the molecular consequences of the interaction between Nkx2-5 and short-term gestational hypoxia, which suggest that reduced Nkx2-5 expression and a prolonged hypoxia-inducible factor 1α response together precipitate embryo death. Our study provides insight into the causes of embryo loss and variable penetrance of monogenic CHD, and raises the possibility that cases of foetal death and CHD in humans could be caused by similar gene-environment interactions.

Reference range of liver corrected T1 values in a population at low risk for fatty liver disease-a UK Biobank sub-study, with an appendix of interesting cases.

PURPOSE: Corrected T1 (cT1) value is a novel MRI-based quantitative metric for assessing a composite of liver inflammation and fibrosis. It has been shown to distinguish between non-alcoholic fatty liver disease (NAFL) and non-alcoholic steatohepatitis. However, these studies were conducted in patients at high risk for liver disease. This study establishes the normal reference range of cT1 values for a large UK population, and assesses interactions of age and gender. METHODS: MR data were acquired on a 1.5 T system as part of the UK Biobank Imaging Enhancement study. Measures for Proton Density Fat Fraction and cT1 were calculated from the MRI data using a multiparametric MRI software application. Data that did not meet quality criteria were excluded from further analysis. Inter and intra-reader variability was estimated in a set of data. A cohort at low risk for NAFL was identified by excluding individuals with BMI ≥ 25 kg/m2 and PDFF ≥ 5%. Of the 2816 participants with data of suitable quality, 1037 (37%) were classified as at low risk. RESULTS: The cT1 values in the low-risk population ranged from 573 to 852 ms with a median of 666 ms and interquartile range from 643 to 694 ms. Iron correction of T1 was necessary in 36.5% of this reference population. Age and gender had minimal effect on cT1 values. CONCLUSION: The majority of cT1 values are tightly clustered in a population at low risk for NAFL, suggesting it has the potential to serve as a new quantitative imaging biomarker for studies of liver health and disease.

Synthetic and Mechanistic Studies of a Versatile Heteroaryl Thioether Directing Group for Pd(II) Catalysis.

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, an arene C-H olefination method was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a "masked olefin" directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C-H olefination as the key step.

Palladium(ii)-catalyzed γ-selective hydroarylation of alkenyl carbonyl compounds with arylboronic acids.

A catalytic γ-selective syn-hydroarylation of alkenyl carbonyl compounds using arylboronic acids has been developed using a substrate directivity approach with a palladium(ii) catalyst. This method tolerates a wide range of functionalized (hetero)arylboronic acids and a variety of substitution patterns on the alkene. Preliminary mechanistic studies suggest that transmetalation is rate-limiting.

Long-term Safety and Efficacy of Conjunctival Pedicle Graft Revision Combined With Repeated Pericardium Allograft for Exposed Glaucoma Drainage Devices.

PURPOSE: To investigate the safety and long-term results of conjunctival pedicle graft (CPG) technique for revision of exposed glaucoma drainage device (GDD). DESIGN: Retrospective noncomparative case series. PATIENTS AND METHODS: All patients with exposed GDD between 2011 and 2016 who underwent tube revision with CPG were included. Data from demographic variables, glaucoma subtype, previous surgeries, GDD type and location, patch graft nature, intraocular pressure, and intraoperative and long-term complications were collected. RESULTS: Eight eyes from 7 patients met the inclusion criteria. Median age was 61 years old (range, 51 to 80), median time to erosion was 23.4 months (range, 5 d to 45.1 mo), median number of operations before exposure was 3 (range, 1 to 5), and 6 tubes had an inferior location (75%). Average follow-up after repair was 24.3 months (range, 5.2 to 59.8 mo). No significant intraoperative adverse events were noted and visual acuity, intraocular pressure, and number of medications remained unchanged at 1 month after repair in all cases. We report 1 case of repeated tube exposure 24 months after CPG in a 51-year-old Afro-Caribbean woman with 5 previous operations. CONCLUSIONS: With an average follow-up of >2 years, we provide additional long-term evidence that CPG is a safe and effective technique for treating exposed tubes. We did not experience any complications and report 1 reexposure case in a young Afro-Caribbean patient with extensive previous conjunctival scarring.

Activation of diverse carbon-heteroatom and carbon-carbon bonds via palladium(II)-catalysed ß-X elimination.

Chemists' ability to synthesize structurally complex, high-value organic molecules from simple starting materials is limited by methods to selectively activate and functionalize strong alkyl C(sp3) covalent bonds. Recent activity has focused on the activation of abundant C-O, C-N and C-C bonds via a mechanistic paradigm of oxidative addition of a low-valent, electron-rich transition metal. This approach typically employs nickel(0), rhodium(I), ruthenium(0) and iron catalysts under conditions finely tuned for specific, electronically activated substrates, sometimes assisted by chelating functional groups or ring strain. By adopting a redox-neutral strategy involving palladium(II)-catalysed C-H activation followed by ß-heteroatom/carbon elimination, we describe here a catalytic method to activate alkyl C(sp3)-oxygen, nitrogen, carbon, fluorine and sulfur bonds with high regioselectivity. Directed hydrofunctionalization of the resultant palladium(II)-bound alkene leads to formal functional group metathesis. The method is applied to amino acid upgrading with complete regioselectivity and moderate to high retention of enantiomeric excess. Low-strain heterocycles undergo strong-bond activation and substitution, giving ring-opened products.

Changes in the physiochemical, microbial, and sensory characteristics of fresh pork sausage containing rosemary and green tea extracts during retail display.

The effects of adding combinations of rosemary (R: 1500, 2000, 2500 ppm) and green tea (G: 100, 200, 300 ppm) extracts in combination with synthetic antioxidants on the physiochemical, microbial, and sensory characteristics of fresh pork sausage were evaluated. R and G improved (P < .05) oxidative stability as evidenced by lower TBARS. R2500 and G300 had fewer PPC than the control at d 7, 14, and 21 of storage. Consumer acceptability scores were greater (P < .05) in sausages with R and G when compared to the control, and the majority of the R and G treatments were liked by 98% of the respondents. Treatment combinations of at least R2000 and G200 were described by positive drivers of liking such as spice-complex, ginger, nutmeg, rosemary flavors and aromas and lower scores for descriptors such as rancid, fruity, and off-flavor/odor. This research demonstrates that rosemary and green tea extracts improved the keeping quality of fresh pork sausage under simulated retail display.

Phacoemulsification plus endoscopic cyclophotocoagulation versus phacoemulsification alone in primary open-angle glaucoma.

PURPOSE: To examine the efficacy and safety of combined phacoemulsification and endoscopic cyclophotocoagulation (phaco-ECP) compared to phacoemulsification alone in patients with primary open-angle glaucoma (POAG). METHODS: We performed a retrospective notes review of 99 consecutive clinical records of patients with POAG from 2 London eye departments. A total of 69 patients who underwent phaco-ECP and 30 sex- and age-matched control patients who underwent cataract surgery alone were included. Data on intraocular pressure (IOP), visual acuity (VA), number of ocular hypotensive medications, and postoperative complications were collected over 12 months. The primary outcome measure was defined as an IOP within normal limits (<21 mm Hg) and at least a 20% reduction in IOP from baseline. RESULTS: Mean IOP was significantly decreased in both groups after 1 year (p<0.001 from baseline). The success rate was significantly higher in the phaco-ECP group (69.6%) than in the phaco group (40%) after 1 year (p = 0.004). Reduction in mean IOP and number of medications was also greater in the phaco-ECP group after 1 year (IOP reduction: 4.5 ± 5.13 mm Hg vs 1.83 ± 3.61 mm Hg; p = 0.007; number of medications reduction: 0.73 ± 0.71 vs 0.23 ± 0.56; p = 0.001). Both groups achieved a similar improvement in VA. There was a higher incidence of minor and self-limiting complications in the phaco-ECP group (p<0.047). CONCLUSIONS: Phaco-ECP resulted in a greater reduction in IOP and number of medications than phacoemulsification alone in POAG.

Chronic radiation exposure as an ecological factor: Hypermethylation and genetic differentiation in irradiated Scots pine populations.

Genetic and epigenetic changes were investigated in chronically irradiated Scots pine (Pinus sylvestris L.) populations from territories that were heavily contaminated by radionuclides as result of the Chernobyl Nuclear Power Plant accident. In comparison to the reference site, the genetic diversity revealed by electrophoretic mobility of AFLPs was found to be significantly higher at the radioactively contaminated areas. In addition, the genome of pine trees was significantly hypermethylated at 4 of the 7 affected sites.

Inhibitors of soluble epoxide hydrolase minimize ischemia-reperfusion-induced cardiac damage in normal, hypertensive, and diabetic rats.

AIM: We designed a study to evaluate the cardioprotective effect of two soluble epoxide hydrolase (sEH) inhibitors, 1-(1-propanoylpiperidin-4-yl)-3-(4-trifluoromethoxy)phenyl)urea (TPPU) and trans-4-{4-[3-(4-trifluoromethoxyphenyl)-ureido]cyclohexyloxy}benzoic acid (t-TUCB), in ischemia-reperfusion (IR) model. METHODS: Cardioprotective effects of the sEH inhibitors were evaluated against IR-induced myocardial damage in hearts from normal, hypertensive, and diabetic rats using Langendorff's apparatus. In addition, the effect of sEH inhibitors on endothelial function was evaluated in vitro and ex vivo using isolated rat thoracic aorta. RESULTS: Ischemia-reperfusion (IR) increased the myocardial damage in hearts from normal rats. IR-induced myocardial damage was augmented in hearts isolated from hypertensive and diabetic rats. Myocardial damage as evident from increase in the activities of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) in heart perfusate was associated with significant decrease in the heart rate and developed tension, and increase in the resting tension in isolated heart. Both sEH inhibitors protected the heart in normal, hypertensive, and diabetic rats subjected to IR injury. The sEH inhibitor t-TUCB relaxed phenylephrine precontracted aorta from normal rats. Relaxant effect of acetylcholine (ACh) was reduced in aortas from diabetic and hypertensive rats compared to normal rats. Pretreatment of sEH inhibitors to diabetic and hypertensive rats increased relaxant effect of ACh on aortas isolated from these rats. CONCLUSIONS: Prophylactic treatment with sEH inhibitors decreased myocardial damage due to IR, hypertension and diabetes, and decreased endothelial dysfunction created by diabetes and hypertension. Therefore, inhibitors of sEH are useful probes to study cardiovascular pathology, and inhibition of the sEH is a potential approach in the management of IR-induced cardiac damage and endothelial dysfunction-related cardiovascular disorders.

Catalytic, Regioselective Hydrocarbofunctionalization of Unactivated Alkenes with Diverse C-H Nucleophiles.

Reactions that forge carbon-carbon (C-C) bonds are the bedrock of organic synthesis, widely used across the chemical sciences. We report a transformation that enables C-C bonds to be constructed from two classes of commonly available starting materials, alkenes and carbon-hydrogen (C-H) bonds. The reaction employs a palladium(II) catalyst and utilizes a removable directing group to both control the regioselectivity of carbopalladation and enable subsequent protodepalladation. A wide range of alkenes and C-H nucleophiles, including 1,3-dicarbonyls, aryl carbonyls, and electron-rich aromatics, are viable reaction partners, allowing Michael-type reactivity to be expanded beyond α,ß-unsaturated carbonyl compounds to unactivated alkenes. Applications of this transformation in drug diversification and natural product total synthesis are described. Stoichiometric studies support each of the proposed steps in the catalytic cycle.

ß,γ-Vicinal Dicarbofunctionalization of Alkenyl Carbonyl Compounds via Directed Nucleopalladation.

A palladium(II)-catalyzed 1,2-dicarbofunctionalization reaction of unactivated alkenes has been developed, wherein a cleavable bidentate directing group is used to control the regioselectivity and stabilize the putative alkylpalladium(II) intermediate. Under the optimized reaction conditions, a broad range of nucleophiles and electrophiles were found to participate in this transformation, providing moderate to high yields. 3-Butenoic acid derivatives containing internal alkenes and α-substituents were reactive substrates, offering a powerful platform for preparing ß,γ-substituted carbonyl compounds with multiple stereocenters.

[Influence of γ-Irradiated Seeds on the Enzyme Activity in Barley Seedlings].

Influence of γ-irradiation of barley seeds (Nur variety) at the doses of 8-50 Gy on catalase, pyruvate kinase, glucose-6-phosphate dehydrogenase, and guaiacol peroxidase activities was studied in the seedlings on the 3, 5 and 7 days after germination. It has been shown that activities of the studied enzymes increase in the dose range that causes the growth stimulation in the seedlings (16-20 Gy).

[Assessment of Cyto- and Genotoxicity of Underground Waters from the Far Eastern Center on Radioactive Waste Treatment Site].

This study has been completed in the frames of activities on the environment assessment in the vicinity of the Far Eastern center (FEC) on radioactive waste treatment (a branch of Fokino, Sysoev Bay). Underground waters collected at the FEC technical site were surveyed both with instrumental techniques and bioassays. Concentrations of some chemicals (ranged to the third hazard category) in the samples collected are over the permitted limits. Activities of 137Cs and 90Sr in waters amount up to 3.8 and 16.2 Bq/l, correspondingly. The integral pollution index is over 1 in all the samples and could amount up to 165. The Allium-test application allows the detection of the sample points where underground waters have an enhanced mutagenic potential. Dependencies between biological effects and pollution levels are analyzed. The findings obtained could be used for the monitoring optimized and decision making on rehabilitation measures to decrease negative influence of the enterprise on the environment.

Directed, Regiocontrolled Hydroamination of Unactivated Alkenes via Protodepalladation.

A directed, regiocontrolled hydroamination of unactivated terminal and internal alkenes is reported. The reaction is catalyzed by palladium(II) acetate and is compatible with a variety of nitrogen nucleophiles. A removable bidentate directing group is used to control the regiochemistry, prevent ß-hydride elimination, and stabilize the nucleopalladated intermediate, facilitating a protodepalladation event. This method affords highly functionalized γ-amino acids in good yields with high regioselectivity.