Получение оксицеллюлозы из хлопковых волокон действием различных окислителей

Проблематика. Розробка технологій виробництва різних за призначенням матеріалів із альтернативних нафті й газу природних джерел сировини, зокрема з целюлози. Мета дослідження. Визначення оптимальних значень технологічних параметрів процесу окиснення бавовняних волокон дією різних окисників – пероксиду водню, Оксону, PINO – на показники якості оксицелюлози. Методика реалізації. Окиснення механічно подрібнених бавовняних волокон розчинами пероксиду водню, Оксону і PINO проводили з барботуванням повітря за допомогою компресора через розчин целюлози в круглодонній колбі, зануреній у водяну баню необхідної температури. Для визначення оптимальних параметрів процесу використовували методи планування експерименту та оптимізації. Результати дослідження. Досліджені окисники для одержання оксицелюлози із бавовняних волокон за збільшенням ефективності розміщуються в такий ряд: пероксид водню – Оксон – PINO. Методом повного факторного експерименту визначено рівняння регресії, які адекватно описують процес отримання оксицелюлози із волокон бавовни дією Оксону і PINO, а за допомогою методу Гаусса–Зейделя – оптимальні значення технологічних параметрів процесу одержання оксицелюлози. Показано, що проведення процесу окиснення бавовняних волокон за оптимальними значеннями технологічних параметрів дає змогу отримати бавовняну оксицелюлозу із вмістом карбоксильних груп до 3 %. Висновки. Одержана оксицелюлоза може використовуватися в медицині як один із компонентів нетоксичних, кровоспинних, антимікробних матеріалів.Background. Development of production technologies of materials for various purposes of alternatives to crude oil and natural gas sources of raw material, in particular cellulose. Objective. To determine the optimal values of technological parameters of cotton fiber oxidation by action of various oxidants — hydrogen peroxide, Oxone, PINO — on quality of oxycellulose. Methods. Oxidation of mechanically chopped cotton fibers by solution of hydrogen peroxide, Oxone and PINO was performed with air bubbling by the compressor through solution of cellulose in round-bottomed flask immersed in a water bath of the required temperature. The methods of experiment planning and optimization were used to determine the optimum process parameters. Results. Studied oxidants for oxycellulose of cotton fibers to increase efficiency are in the following order: hydrogen peroxide — Oxone — PINO. The method of full factorial experiment was used to determine the adequate regression equations that describe the process of oxycellulose obtaining by action of Oxone and PINO, and the Gauss-Seidel method was used to determine the optimal values of technological parameters of oxycellulose obtaining. It is shown that oxidation of cotton fibers for optimal values of technological parameters allows getting oxycellulose with the content of carboxyl groups to 3 %. Conclusions. The obtained oxycellulose can be used in medicine as a component of non-toxic, hemostatic, antimicrobial materials.Проблематика. Разработка технологий производства различных по назначению материалов из альтернативных нефти и газу природных источников сырья, в частности из целлюлозы. Цель исследования. Определение оптимальных значений технологических параметров процесса окисления хлопковых волокон действием различных окислителей – пероксида водорода, Оксона, PINO – на показатели качества оксицелюлозы. Методика реализации. Окисление механически измельченных хлопковых волокон растворами пероксида водорода, Оксона и PINO проводили с барботированием воздуха при помощи компрессора через раствор целлюлозы в круголодонной колбе, погруженной в водяную баню необходимой температуры. Для определения оптимальных параметров процесса использовали методы планирования эксперимента и оптимизации. Результаты исследования. Исследованные окислители для получения оксицеллюлозы из хлопковых волокон по увеличению эффективности располагаются в следующий ряд: пероксид водорода – Оксон – PINO. Методом полного факторного эксперимента определены уравнения регрессии, адекватно описывающие процесс получения оксицеллюлозы из волокон хлопка действием Оксона и PINO, а с помощью метода Гаусса–Зейделя – оптимальные значения технологических параметров процесса получения оксицеллюлозы. Показано, что проведение процесса окисления хлопковых волокон по оптимальным значениям технологических параметров позволяет получить оксицеллюлозу с содержанием карбоксильных групп до 3 %. Выводы. Полученная оксицеллюлоза может использоваться в медицине как один из компонентов нетоксичных, кровоостанавливающих, антимикробных материалов

TNF-alpha Is Required for the Attraction of Mesenchymal Precursors to White Adipose Tissue in Ob/ob Mice

Most adult tissues harbour a stem cell subpopulation (Mesenchymal Precursors or MPs) that represent a small proportion of the total cell number and have the potential to differentiate into several cell types within the mesenchymal lineage. In adipose tissue, adipocytes account for two-thirds of the total cell number. The remaining cells include blood and endothelial cells, along with adipocyte precursors (adipose MPs). Obesity is defined as an excess of body fat that frequently results in a significant impairment of health. The ob/ob mice bear a mutation in the ob gene that causes a deficiency in the hormone leptin and hence obesity. Here, we present evidence that ob/ob mice have a dramatic decrease in the resident MP pool of several tissues, including squeletal muscle, heart, lung and adipose tissue. Moreover, we show that that there is a migration of MP cells from distant organs, as well as homing of these cells to the adipose tissue mass of the ob/ob mice. We call this process adipotaxis. Once in the adipose tissue, migrant MPs undergoe adipose differentiation, giving rise to new differentiated adipocytes within the adipose mass. Finally, we provide evidence that adipotaxis is largely explained by the production of high levels of Tumor Necrosis Factor-alpha (TNF-α) within the ob/ob adipose tissue. The therapeutic implications for human obesity as well as for regenerative medicine are further discussed in this paper

Average Household Exposure to Newspaper Coverage about the Harmful Effects of Hormone Therapy and Population-Based Declines in Hormone Therapy Use

BACKGROUND: The news media facilitated the rapid dissemination of the findings from the estrogen plus progestin therapy arm of the Women’s Health Initiative (EPT-WHI). OBJECTIVE: To examine the relationship between the potential exposure to newspaper coverage and subsequent hormone therapy (HT) use. DESIGN/POPULATION: Population-based cohort of women receiving mammography at 7 sites (327,144 postmenopausal women). MEASUREMENTS: The outcome was the monthly prevalence of self-reported HT use. Circulation data for local, regional, and national newspapers was used to create zip-code level measures of the estimated average household exposure to newspaper coverage that reported the harmful effects of HT in July 2002. RESULTS: Women had an average potential household exposure of 1.4 articles. There was substantial variation in the level of average household exposure to newspaper coverage; women from rural sites received less than women from urban sites. Use of HT declined for all average potential exposure groups after the publication of the EPT-WHI. HT prevalence among women who lived in areas where there was an average household exposure of at least 3 articles declined significantly more (45 to 27%) compared to women who lived in areas with <1 article (43 to 31%) during each of the subsequent 5 months (relative risks 0.86–0.92; p < .006 for all). CONCLUSIONS: Greater average household exposure to newspaper coverage about the harms associated with HT was associated with a large population-based decline in HT use. Further studies should examine whether media coverage directly influences the health behavior of individual women

17-beta-Estradiol in relation to age at menarche and adult obesity in premenopausal women

BACKGROUND: We hypothesize that premenopausal endogenous estradiol may be associated with age at menarche and adult overweight and obesity, potentially contributing to breast cancer risk. METHODS: We assessed age at menarche by questionnaire among 204 healthy Norwegian women, aged 25 – 35 years. Measures of body composition included body mass index (BMI, kg/m2), waist circumference (WC, cm), waist-to-hip ratio (WHR) and fat percentage dual energy X-ray absorptiometry, (DEXA). Daily salivary 17-b-estradiol (E2) concentrations were collected throughout one entire menstrual cycle and assessed by radioimmunoassay (RIA). Linear regression analyses and linear mixed models for repeated measures were used and potential confounding factors and effect modifiers were tested. RESULTS: Among women with an early age at menarche (12 years), the overall mean salivary E2 concentration increased by 3.7 pmol/l (95% confidence interval, 1.8 – 5.7 pmol/l) with each 9.8 cm (1 SD) increase in WC, which represents a 20.7% change in the mean for the total group. Among the same early maturers, a 1 SD (0.06) change in WHR was directly associated with a 24.0% change in mean E2 concentration for the total group. CONCLUSIONS: Our findings support the hypothesis that early age at menarche, together with adult overweight and obesity, result in high levels of 17-b-estradiol throughout the menstrual cycle.AnthropologyHuman Evolutionary Biolog

MRI roadmap-guided transendocardial delivery of exon-skipping recombinant adeno-associated virus restores dystrophin expression in a canine model of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) cardiomyopathy patients currently have no therapeutic options. We evaluated catheter-based transendocardial delivery of a recombinant adeno-associated virus (rAAV) expressing a small nuclear U7 RNA (U7smOPT) complementary to specific cis-acting splicing signals. Eliminating specific exons restores the open-reading frame resulting in translation of truncated dystrophin protein. To test this approach in a clinically relevant DMD model, golden retriever muscular dystrophy (GRMD) dogs received serotype 6 rAAV-U7smOPT via the intracoronary or transendocardial route. Transendocardial injections were performed with an injection-tipped catheter and fluoroscopic guidance using X-ray fused with MRI (XFM) roadmaps. Three months after treatment, tissues were analyzed for DNA, RNA, dystrophin protein, and histology. Whereas intracoronary delivery did not result in effective transduction, transendocardial injections, XFM guidance, enabled 30±10 non-overlapping injections per animal. Vector DNA was detectable in all samples tested and ranged from 3000 vector genome copies per cell. RNA analysis, western blot analysis, and immunohistology demonstrated extensive expression of skipped RNA and dystrophin protein in the treated myocardium. Left ventricular function remained unchanged over a three-month follow-up. These results demonstrated that effective transendocardial delivery of rAAV-U7smOPT was achieved using XFM. This approach restores an open reading frame for dystrophin in affected dogs and has potential clinical utility

Estimation of Isolation Times of the Island Species in the Drosophila simulans Complex from Multilocus DNA Sequence Data

Background: The Drosophila simulans species complex continues to serve as an important model system for the study of new species formation. The complex is comprised of the cosmopolitan species, D. simulans, and two island endemics, D. mauritiana and D. sechellia. A substantial amount of effort has gone into reconstructing the natural history of the complex, in part to infer the context in which functional divergence among the species has arisen. In this regard, a key parameter to be estimated is the initial isolation time (t) of each island species. Loci in regions of low recombination have lower divergence within the complex than do other loci, yet divergence from D. melanogaster is similar for both classes. This might reflect gene flow of the lowrecombination loci subsequent to initial isolation, but it might also reflect differential effects of changing population size on the two recombination classes of loci when the low-recombination loci are subject to genetic hitchhiking or pseudohitchhiking Methodology/Principal Findings: New DNA sequence variation data for 17 loci corroborate the prior observation from 13 loci that DNA sequence divergence is reduced in genes of low recombination. Two models are presented to estimate t and other relevant parameters (substitution rate correction factors in lineages leading to the island species and, in the case of the 4-parameter model, the ratio of ancestral to extant effective population size) from the multilocus DNA sequence data. Conclusions/Significance: In general, it appears that both island species were isolated at about the same time, here estimated at,250,000 years ago. It also appears that the difference in divergence patterns of genes in regions of low an

Gene Expression Disruptions of Organism versus Organ in Drosophila Species Hybrids

Hybrid dysfunctions, such as sterility, may result in part from disruptions in the regulation of gene expression. Studies of hybrids within the Drosophila simulans clade have reported genes expressed above or below the expression observed in their parent species, and such misexpression is associated with male sterility in multigenerational backcross hybrids. However, these studies often examined whole bodies rather than testes or had limited replication using less-sensitive but global techniques. Here, we use a new RNA isolation technique to re-examine hybrid gene expression disruptions in both testes and whole bodies from single Drosophila males by real-time quantitative RT-PCR. We find two early-spermatogenesis transcripts are underexpressed in hybrid whole-bodies but not in assays of testes alone, while two late-spermatogenesis transcripts seem to be underexpressed in both whole-bodies and testes alone. Although the number of transcripts surveyed is limited, these results provide some support for a previous hypothesis that the spermatogenesis pathway in these sterile hybrids may be disrupted sometime after the expression of the early meiotic arrest genes

Short-Term Exposure of Multipotent Stromal Cells to Low Oxygen Increases Their Expression of CX3CR1 and CXCR4 and Their Engraftment In Vivo

The ability of stem/progenitor cells to migrate and engraft into host tissues is key to their potential use in gene and cell therapy. Among the cells of interest are the adherent cells from bone marrow, referred to as mesenchymal stem cells or multipotent stromal cells (MSC). Since the bone marrow environment is hypoxic, with oxygen tensions ranging from 1% to 7%, we decided to test whether hypoxia can upregulate chemokine receptors and enhance the ability of human MSCs to engraft in vivo. Short-term exposure of MSCs to 1% oxygen increased expression of the chemokine receptors CX3CR1and CXCR4, both as mRNA and as protein. After 1-day exposure to low oxygen, MSCs increased in vitro migration in response to the fractalkine and SDF-1α in a dose dependent manner. Blocking antibodies for the chemokine receptors significantly decreased the migration. Xenotypic grafting into early chick embryos demonstrated cells from hypoxic cultures engrafted more efficiently than cells from normoxic cultures and generated a variety of cell types in host tissues. The results suggest that short-term culture of MSCs under hypoxic conditions may provide a general method of enhancing their engraftment in vivo into a variety of tissues

Risk of breast cancer in young women in relation to body size and weight gain in adolescence and early adulthood

Findings have been inconsistent on effects of adolescent body size and adult weight gain on risk of breast cancer in young women. These relations were examined in a population-based case control study of 1590 women less than 45 years of age newly diagnosed with breast cancer during 1990–1992 in three areas of the US and an age-matched control group of 1390 women. Height and weight were measured at interview and participants asked to recall information about earlier body size. Logistic regression was used to estimate the relative risk of breast cancer adjusted for other risk factors. Women who were either much heavier or lighter than average in adolescence or at age 20 were at reduced risk. Weight gain after age 20 resulted in reduced risk, but the effect was confined to early-stage and, more specifically, lower grade breast cancer. Neither the risk reduction nor the variation by breast cancer stage or grade was explained by the method of cancer detection or by prior mammography history. These findings suggest that relations between breast cancer risk in young women and body weight at different ages is complex and that the risk reduction with adult weight gain is confined to less aggressive cancers. © 1999 Cancer Research Campaig