Cadmium tolerance and removal in the marine microalga
Dunaliella salina were studied in cultures exposed to different metal concentrations (5–120
mg
Cd
l
−1) for 96
h. This microalga can be included ...in the group of microalgal species most tolerant to cadmium due to the high value of EC50 that it possesses (48.9
mg
Cd
l
−1 at 96
h of culture). The greater percentage of cadmium removed was obtained in cultures exposed to 5
mg
Cd
l
−1 at 96
h, but removing only 11.3% of the added cadmium. In all cultures, the quantity of cadmium removed intracellularly was much lower than the bioadsorbed quantity and it was proportional to the sulfhydryl group levels. Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of cadmium by living cells of
D. salina.
The organocatalyzed ring-opening polymerization (ROP) of various 4-alkoxymethylene-β-propiolactones (BPL
OR
s; R = CH
2
CH&z.dbd;CH
2
(All), CH
2
Ph (Bn), (CH
2
)
3
CH
3
(
n
Bu), SiMe
2
t
Bu (TBDMS)) ...towards the formation of the corresponding poly(hydroxyalkanoate)s (PHAs; poly(BPL
OR
)s (PBPL
OR
s)) is investigated under mild operating conditions (neat, 60 °C), simply using basic organocatalysts of the guanidine (1,5,7-triazabicyclo4.4.0dec-5-ene, TBD), amidine (1,8-diazabicyclo5.4.0-undec-7-ene, DBU) or phosphazene (2-
tert
-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2diazaphosphorine, BEMP) type. The polymerization proceeds basically at the same rate as the alike organocatalyzed ROP of related β-lactones (especially the ubiquitous β-butyrolactone (BL) and alkyl β-malolactonates (MLA
R
s)), with BEMP being significantly more active than TBD and DBU. Insights into the polymerization mechanisms are gained through detailed 1D/2D NMR spectroscopy and MALDI-ToF mass spectrometry analyses of the resulting PBPL
OR
s and in particular through the identification of the nature of the end-capping groups. Each of the three organobases promotes the polymerization in its own way, as dictated by either its basic, nucleophilic or dual behavior.
The organocatalyzed ROP of some 4-alkoxymethylene-β-propiolactones (BPL
OR
s) towards the formation of the corresponding poly(hydroxyalkanoate)s (PHAs; PBPL
OR
s) is investigated simply using basic organocatalysts of the guanidine (TBD), amidine (DBU) or phosphazene (BEMP) type.
To conduct a meta-analytic review of HIV interventions for people living with HIV (PLWH) to determine their overall efficacy in reducing HIV risk behaviours and identify intervention characteristics ...associated with efficacy.
Comprehensive searches included electronic databases from 1988 to 2004, hand searches of journals, reference lists of articles, and contacts with researchers. Twelve trials met the stringent selection criteria: randomization or assignment with minimal bias, use of statistical analysis, and assessment of HIV-related behavioural or biologic outcomes at least 3 months after the intervention. Random-effects models were used to aggregate data.
Interventions significantly reduced unprotected sex odds ratio (OR), 0.57; 95% confidence interval (CI) 0.40-0.82 and decreased acquisition of sexually transmitted diseases (OR, 0.20; 95% CI, 0.05-0.73). Non-significant intervention effects were observed for needle sharing (OR, 0.47, 95% CI, 0.13-1.71). As a whole, interventions with the following characteristics significantly reduced sexual risk behaviours: (1) based on behavioural theory; (2) designed to change specifically HIV transmission risk behaviours; (3) delivered by health-care providers or counsellors; (4) delivered to individuals; (5) delivered in an intensive manner; (6) delivered in settings where PLWH receive routine services or medical care; (7) provided skills building, or (8) addressed a myriad of issues related to mental health, medication adherence, and HIV risk behaviour.
Interventions targeting PWLH are efficacious in reducing unprotected sex and acquisition of sexually transmitted diseases. Efficacious strategies identified in this review should be incorporated into community HIV prevention efforts and further evaluated for effectiveness.
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•The ring-opening polymerization of (substituted) d-valerolactones is studied.•Alkali metal alkoxides homopolymerize the 5-Me substituted δ-valerolactone.•PHL oligomers and ...P(HL-co-d-valerolactone) random copolymers are recovered.•HL is more reactive than the analogous 1,5-alkyl 6-membered δ-valerolactones.•New insights into the ring-opening polymerizability of substituted δ-valerolactone.
The ring-opening polymerization (ROP) of bio-derived six-membered (substituted) δ-valerolactones, including the 5-Me substituted δ-valerolactone (aka δ-hexalactone (HL)), 2-ethylidene-6-hepten-5-olide (EVL), 2-ethylheptane-5-olide (EHO) and the novel 2-ethylidene-6-heptan-5-olide (MH), is investigated. In comparison to the ubiquitous unsubstituted δ-valerolactone (VL), the presence of a substituent on the lactone ring appears to significantly affect the polymerizability of the monomer, whichever the catalyst/initiator system or the operating conditions. Typical Brönsted acids, organocatalysts or Lewis acidic metal complexes revealed hardly active in the ROP of HL, most likely originating from polymerization/depolymerization issues. Better efficiency was achieved from alkali metal complexes, especially using NaOMe (1–2.5 mol%) from which high-to-quantitative HL conversion was reached within 18 h at 60 °C. Oligomers (M̅n,NMR ≤ 3800 g mol−1, ÐM = 1.22–1.36) were thus synthesized from ROP, as supported by NMR spectroscopy, SEC and MALDI-ToF mass spectrometry analyses. P(HL-co-VL) random copolymers incorporating up to 44 mol% of HL into PVL were next synthesized from the simultaneous HL/VL copolymerization mediated by NaOMe (M̅n,NMR up to 9700 g mol−1, ÐM = 1.21–1.40). The ROP of the sustainable CO2/butadiene-derived EVL, EHO or MH –the original semi-hydrogenated parent lactone–, remained unsuccessful, regardless of the catalytic system.
The growing prevalence of overweight/obesity in adolescents highlights the significance of studying metabolic syndrome (MetS) in increasingly sedentary adolescents. To date, no study in Sudan has ...examined the association between MetS and physical activity (PA) among adolescents. This study aimed to assess the association between MetS and its components and PA among Sudanese early adolescents. A cross-sectional assessment was conducted from to 2018 to 2019 on a sample of 921 primary school students from Khartoum State, Republic of Sudan. MetS was defined according to the International Diabetes Federation criteria and a standardized questionnaire was used to assess PA. Metabolic equivalents of task were calculated, and levels of different intensities of PA (tertiles) were identified accordingly. The association between PA and MetS and its components was assessed using a logistic regression model. The participants comprised 388 boys and 533 girls with a mean age of 12.59 ± 1.21 years. The prevalence of MetS was significantly higher in subjects in the 1st PA tertile (least active) than in the 2nd and 3rd (most active) tertiles of PA, and this difference was observed in both boys and girls. After adjusting for other study factors, the odds of MetS among adolescents in the 1st PA tertile were 7 times higher than those in the highest PA tertile (adjusted odds ratio = 7.01, 95% confidence interval: 1.48, 32.99). A physically inactive lifestyle was associated with higher odds of MetS and its components, especially waist circumference and triglyceride levels, in Sudanese early adolescents. This study highlights the importance of promoting PA in this age group.
Exploring the osteogenic effect of different bone-loading sports is particular relevant to understand the interaction between skeletal muscle and bone health during growth. This study aimed to ...compare total and regional bone and soft-tissue composition between female adolescent swimmers (n=20, 15.71±0.93 years) and volleyball players (n=26, 16.20±0.77 years).
Dietary intake was obtained using food frequency questionnaires. Body size was given by stature, sitting height, and body mass. Six skinfolds were measured. Bone mineral content (BMC) and density (BMD), lean soft tissue, and fat tissue were assessed using dual-energy X-ray absorptiometry. Pearson's product moment correlation coefficients were calculated to examine the relationships among variables, by type of sport. Comparisons between swimmers and volleyball players were performed using student t-tests for independent samples and multivariate analysis of covariance (controlling for age, training history and body size).
Swimmers (BMC: 2328±338 g) and volleyball players (BMC: 2656±470 g) exceeded respectively by 2.1 and 2.8 standard deviation scores the average of international standards for whole body BMC of healthy adolescents. Years of training in swimmers were positively related to the upper limbs BMC (r=+0.49, p<0.05). In volleyball players, years of training correlated significantly with lower limbs BMD (r=+0.43, p<0.05). After adjustments for potential confounders, moderate differences (ES-r=0.32) between swimmers and volleyball players were noted in BMD at the lower limbs (volleyball players: +0.098 g∙cm
, +7.8%).
Youth female athletes who participate in high-intensity weight-loading activities such as volleyball exhibit moderately higher levels of BMD at the lower limbs compared to non-loading sports such as swimming.
In recent years, health monitoring consists of the periodic observation and analysis of existing systems to predict and avoid structural breakdown, thereby saving lives and significantly lowering the ...cost of structural maintenance and repair. Normally, non-destructive testing techniques and sensor technology are used to detect damage in concrete structures are expensive in nature. Self-diagnosing or smart concrete has emerged a new paradigm in concrete research for damage detection. Smart concrete was cast by blending functional fillers such as carbon black, and steel fibers with concrete to improve the performance. Under various load conditions, the mechanical properties of the proposed smart concrete were examined. The electrical resistance of smart concrete was measured using the Four Probe Method and the Arduino UNO software. SEM and XRD were used to investigate the microstructures of intrinsically smart concrete. Thermogravimetric analysis was employed as a Non-Destructive Testing method to observe the hydration process. Furthermore, the obtained data were linked with the electrical resistivity of the smart concrete to assess corrosion damage. The electrical resistivity method is also an economical method and effective method to monitor the rate of corrosion.
Nuclear Powerplants are planned and designed to withstand high internal, external pressures and impact loads. International Atomic Energy Agency recommends Design Extension Condition (Impact of ...Missile or Aircraft) that is a mandatory condition to be fulfilled by Containment structure. In this Finite Element Analytical study, wall joint section of containment structure is modelled and analysed for Missile body impact, and it is observed that, the surface induced pressure in wall section is dynamic in nature, as it varies with respect to time and load. By obtained 3D simulation and contour pattern on PCC panel, it is found that the induced stress is bending pressure.
I/R injury is a major deleterious factor of successful kidney transplantation (KTx). Carbon monoxide (CO) is an endogenous gaseous regulatory molecule, and exogenously delivered CO in low ...concentrations provides potent cytoprotection. This study evaluated efficacies of CO exposure to excised kidney grafts to inhibit I/R injury in the pig KTx model. Porcine kidneys were stored for 48 h in control UW or UW supplemented with CO (CO‐UW) and autotransplanted in a 14‐day follow‐up study. In the control UW group, animal survival was 80% (4/5) with peak serum creatinine levels of 12.0 ± 5.1 mg/dL. CO‐UW showed potent protection, and peak creatinine levels were reduced to 6.9 ± 1.4 mg/dL with 100% (5/5) survival without any noticeable adverse event or abnormal COHb value. Control grafts at 14 days showed significant tubular damages, focal fibrotic changes and numerous infiltrates. The CO‐UW group showed significantly less severe histopathological changes with less TGF‐β and p‐Smad3 expression. Grafts in CO‐UW also showed significantly lower early mRNA levels for proinflammatory cytokines and less lipid peroxidation. CO in UW provides significant protection against renal I/R injury in the porcine KTx model. Ex vivo exposure of kidney grafts to CO during cold storage may therefore be a safe strategy to reduce I/R injury.
Porcine kidney grafts preserved in CO‐containing UW solution are protected from ischemia/reperfusion injury and have improved function after transplantation compared to those with untreated UW solution.
The trillions of microorganisms residing in the human body display varying degrees of compositional and functional diversities within and between individuals and contribute significantly to host ...physiology and susceptibility to disease. Microbial species present in the vaginal milieu of reproductive age women showed a large personal component and varies widely in different ethnic groups at the taxonomic, genomic, and functional levels. Lactobacillus iners, L. crispatus, L. gasseri, L. jensenii, and L. johnsonii are most frequently detected bacterial species in the vaginal milieu of reproductive age women. However, we currently lack (i) an understanding of the baseline vaginal microbiota of reproductive age Indian women, (ii) the extent of taxonomic and functional variations of vaginal microbiota between individuals and (iii) the genomic repertoires of the dominant vaginal microbiota associated with the Indian subjects. In our study, we analyzed the metagenome of high vaginal swab (HVS) samples collected from 40 pregnant Indian women enrolled in the GARBH-Ini cohort. Composition and abundance of bacterial species was characterized by pyrosequencing 16S rRNA gene. We identified 3067 OTUs with = 10 reads from four different bacterial phyla. Several species of lactobacilli were clustered into three community state types (CSTs). L. iners, L. crispatus, L. gasseri, and L. jensenii are the most frequently detected Lactobacillus species in the vaginal environment of Indian women. Other than Lactobacillus, several species of Halomonas were also identified in the vaginal environment of most of the women sampled. To gain genomic and functional insights, we isolated several Lactobacillus species from the HVS samples and explored their whole genome sequences by shotgun sequencing. We analyzed the genome of dominant Lactobacillus species, L. iners, L. crispatus, L. gasseri, and L. paragesseri to represent the CSTs and identify functions that may influence the composition of complex vaginal microbial ecology. This study reports for the first time the vaginal microbial ecology of Indian women and genomic insights into L. iners, L. crispatus, L. gasseri, and L. paragesseri commonly found in the genital tract of reproductive age women.
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