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1.
Different arabinosides and ribosides, viz. Ara‐DDA or 9(1‐β‐d‐arabinofuranosyl) 1,3‐dideazaadenine (6), Ara‐NDDP or 9(1‐β‐d‐arabinofuranosyl) 4‐nitro‐1,3‐dideazapurine (7), Ara‐DKP or 1(1‐β‐d‐arabinofuranosyl) diketopiperazine (8), Ribo‐DDA or 9(1‐β‐d‐ribofuranosyl) 1,3‐dideazaadenine (9) and Ribo‐NDDP or 9(1‐β‐d‐ribofuranosyl) 4‐nitro‐1,3‐dideazapurine (10) have been synthesized as probable antiviral agents. The arabinosides have been synthesized using the catalyst TDA‐1 that causes stereospecific formation of β‐nucleosides while a one‐pot synthesis procedure was adopted for the synthesis of the ribonucleosides where β‐anomers were obtained in higher yields. All the five nucleoside analogs have been screened for antiviral property against HIV‐1 (IIIB), HSV‐1 and 2, parainfluenza‐3, reovirus‐1 and many others. It was observed that arabinosides had greater inhibitory action than ribosides. The compound 7 or Ara‐NDDP has shown maximum inhibition of HIV‐1 replication than the rest of the molecules with an IC50 of 79.4 µg/mL.  相似文献   

2.
Some 4′‐C‐ethynyl‐2′‐deoxy purine nucleosides showed the most potent anti‐HIV activity among the series of 4′‐C‐substituted 2′‐deoxynucleosides whose 4′‐C‐substituents were methyl, ethyl, ethynyl and so on. Our hypothesis is that the smaller the substituent at the C‐4′ position they have, the more acceptable biological activity they show. Thus, 4′‐C‐cyano‐2′‐deoxy purine nucleosides, whose substituent is smaller than the ethynyl group, will have more potent antiviral activity. To prove our hypothesis, we planned to develop an efficient synthesis of 4′‐C‐cyano‐2′‐deoxy purine nucleosides (4′‐CNdNs) and 4′‐C‐ethynyl‐2′‐deoxy purine nucleosides (4′‐EdNs). Consequently, we succeeded in developing an efficient synthesis of six 2′‐deoxy purine nucleosides bearing either a cyano or an ethynyl group at the C‐4′ position of the sugar moiety from 2′‐deoxyadenosine and 2,6‐diaminopurine 2′‐deoxyriboside. Unfortunately, 4′‐C‐cyano derivatives showed lower activity against HIV‐1, and two 4′‐C‐ethynyl derivatives suggested high toxicity in vivo.  相似文献   

3.
The nitric oxide (NO) system is involved in the regulation of the cardiovascular system in controlling central and peripheral vascular tone and cardiac functions. It was the aim of this study to investigate in wild‐type C57BL/6 and endothelial nitric oxide synthase (eNOS) knock‐out mice (eNOS‐/‐) the contribution of NO on the circadian rhythms in heart rate (HR), motility (motor activity [MA]), and body temperature (BT) under various environmental conditions. Experiments were performed in 12∶12 h of a light:dark cycle (LD), under free‐run in total darkness (DD), and after a phase delay shift of the LD cycle by ?6 h (i.e., under simulation of a westward time zone transition). All parameters were monitored by radiotelemetry in freely moving mice. In LD, no significant differences in the rhythms of HR and MA were observed between the two strains of mice. BT, however, was significantly lower during the light phase in eNOS‐/‐ mice, resulting in a significantly greater amplitude. The period of the free‐running rhythm in DD was slightly shorter for all variables, though not significant. In general, rhythmicity was greater in eNOS‐/‐ than in C57 mice both in LD and DD. After a delay shift of the LD cycle, HR and BT were resynchronized to the new LD schedule within 5–6 days, and resynchronization of MA occurred within 2–3 days. The results in telemetrically instrumented mice show that complete knock‐out of the endothelial NO system—though expressed in the suprachiasmatic nuclei and in peripheral tissues—did not affect the circadian organization of heart rate and motility. The circadian regulation of the body temperature was slightly affected in eNOS‐/‐ mice.  相似文献   

4.
New acylated 5‐thio‐β‐d‐glucopyranosylimino‐disusbstituted 1,3,4‐thiadiazols 8, and 11 were prepared, via spontaneous rearrangements, by cycloaddition of the glycosyl isothiocyanate 2 with the reactive intermediates 1‐aza‐2‐azoniaallene hexachloroantimonates 4 and 6, respectively. Reaction of 2 with aminoacetone or chloroethylamine afforded the acylated 5‐thio‐β‐d‐glucopyranosyl‐4‐imidazoline‐2‐thione nucleoside 16 and glucopyranosylamino‐2‐thiazoline derivative 18, respectively. Deblocking of 8, 11, 17 and 19 furnished the free nucleoside analogues 9, 12, 18 and 20, respectively. Analogously, treatment of 2 with chloroethylamine in the 1:2 ratio afforded the thioureylendisaccharide 21. No in vitro antiviral activity against HIV‐1, HIV‐2, human cytomegallovirus (HMCV), has been found for the new synthesized compounds.  相似文献   

5.
The aim of this study was to examine sex differences in sleep‐time preference by age among Italian pre‐adolescents, adolescents, and adults. The final sample consisted of 8,972 participants (5,367 females and 3,605 males) from 10 to 87 yrs of age. To assess preferred sleep habits, we considered the answers to the open‐ended questions of the Morningness‐Eveningness Questionnaire (MEQ). In agreement with previous studies, we found that sleep‐time preference started to shift toward eveningness from the age of 13 yrs. Females reached their peak in eveningness earlier (about 17 yrs of age) than males (about 21 yrs of age). Thereafter, the ideal sleep‐time preference advanced in men and women with increasing age. Females presented a more significant advanced sleep phase than males only during the years when sexual hormones are typically active. Moreover, females reported a longer ideal sleep duration than males across all age groups examined, except in over 55 yrs one. (Author correspondence: )  相似文献   

6.
Large‐scale construction work often requires people to work longer daily hours and more than the ordinary five days in a row. In order to minimize transportation times and optimize the use of personnel, workers are sometimes asked to live in temporary building‐site camps in the proximity of the work site. However, little is known about the biological and psychological effects of this experience. The objective of the present study was to investigate whether exposure to long work hours and extended workweeks while living in building‐site camps in between work shifts was associated with a build‐up of increased complaints of poor sleep, daytime sleepiness, physical exertion, and fatigue across a two‐week work cycle. Two groups of construction workers were examined. The camp group of 13 participants (mean age: 42±11 S.D. yrs) lived in building‐site camps and worked extended hours (between 07:00 and 18:00 h) and extended workweeks (six days in a row, one day off, five days in a row, nine days off). The home group of 16 participants (mean age 40±9 yrs) worked ordinary hours between 07:00 and 15:00 h and returned home after each workday. Self‐ratings of daytime sleepiness (Karolinska Sleepiness Scale), physical exertion (Borg CR‐10), and mood were obtained six or seven times daily during two workweeks. Fatigue ratings were obtained once daily in the evening, and ratings of sleep disturbances were obtained once daily in the morning with the Karolinska Sleep Diary. Data were evaluated in a repeated measures design. The results showed that both groups reported a similar level of daytime sleepiness, physical exertion, and mood across workdays and time points within a workday (all three‐way interactions had p>0.898). Although the home group reported earlier wake‐up times, the pattern of sleep disturbance ratings across the workdays did not differ between the groups. Both groups reported few sleep disturbances and good mood. However, the camp group reported higher physical exertion already at the start of work and showed a more gentle increase in ratings during the work shift and a smaller decline between the end of work and bedtime. The camp group also reported higher fatigue scores than the home group. However, none of the groups showed signs of increasing ratings in the progress of the two workweeks. For both groups, the ratings of daytime sleepiness formed a U‐shaped pattern, with the highest scores at awakening and at bedtime. Yet, the camp group reported higher daytime sleepiness than the home group at lunch break and at the second break in the afternoon. In conclusion, there were no signs of fatigue build‐up or accumulation of daytime sleepiness, physical exertion, or sleep disturbances in either group. Despite the fact that the camp group showed some signs of having trouble in recuperating in between work shifts, as indicated by the higher physical exertion ratings at the start of work, higher fatigue scores, and higher daytime sleepiness, the results constitute no real foundation for altering the camp group's current work schedule and living arrangements.  相似文献   

7.
Drawing on the work of Edward Said and James Clifford, this article discusses the theoretical and practical possibilities for producing images of “otherness” which do not participate in an Orientalist discourse. Works by two avant‐garde filmmakers, Leslie Thornton and Trinh T. Minh‐ha, are examined in the light of these theoretical discussions. While avant‐garde film practice is no guarantee of escaping the pitfalls of Orientalism or cultural relativism, selective viewing of avant‐garde work may provide useful models for visual production.  相似文献   

8.
In view of biological activities of azole nucleosides and apio‐dideoxynucleoside, novel apio nucleoside analogues (1 and 2) with thiazole and triazole base moiety were synthesized using 2,3‐O‐isopropylidene‐apio‐β‐d‐furanose (3), which was prepared from d‐mannose.  相似文献   

9.
Carl‐Ulrik Schierup 《Ethnos》2013,78(3-4):173-198
This article analyzes the role of self‐control, moral and ethical doctrines in the rise of individualist world‐view in Finland. In the Finnish case, the formation of the modern individual was closely linked with the temperance movement, the ideology of which is therefore used as an illustrative example. The guiding line in the article is not to treat self‐control as a theoretical concept used in analyzing individual behavior, but as a legitimation of an increasing use of a utilitarian framework. The author discusses the developments in Finnish individualist world‐view by analyzing the main turning points in Finnish notions about drinking. First he discusses the end of the 19th century and the beginning of the 20th century, the era of the strength of Finnish temperance movement. Secondly he analyzes the way in which conceptions about drinking changed when the temperance movement lost its appeal to the masses.  相似文献   

10.
Temporal density‐dependent parasitism appears to explain the development of some pest‐ and pathogen‐suppressive soils. In many examples, an enrichment of hosts (soil‐borne pests or pathogens) precedes and supports a build up of beneficial parasites in perennial crops or in monocultures, and the population dynamics of hosts and parasites may be described in epidemiological terms. Although the examples support the concept of a balance of nature based on density‐dependent regulation, we lack detailed understanding of the processes that drive these beneficial epidemics. In addition, the epidemics develop slowly and often do not provide the control expected by farmers. Current research, therefore, emphasizes inundative release of beneficial agents. Nevertheless, we should study epidemics in soil in order to learn how they might be enhanced; to learn how better to utilize inoculum that is inundatively added to soil; and to contribute to the general discussion of population biology and regulation.  相似文献   

11.
Compared to younger adults, seniors (≥60 yrs) often adopt a highly regular lifestyle, perhaps as an adaptive response to age‐related changes in their sleep and circadian rhythms. At baseline, diary measures of lifestyle regularity (SRM‐5) were obtained from 104 seniors of three separate groups. Thirty‐three subjects were challenged by spousal bereavement or the need to care for a spouse at home with dementia (Challenged); 33 were suffering from formally diagnosed (DSM‐IV) insomnia (Insomnia); and 38 were healthy, well‐functioning older seniors in the second half of their eighth decade of life or later (Healthy Older). The objective of this study was to determine whether lifestyle regularity increased as a function of age within each of these three senior groups. Overall, age was significantly correlated with SRM‐5 (r=0.41, p<0.001), with the SRM score increasing by 0.67 units/decade. The same was true for the Challenged and Insomnia groups, which also showed a significant correlation between SRM and age (Challenged: r=0.48, p<0.01; Insomnia: r=0.36, p<0.05), though with a slightly faster rate of SRM increase in the Challenged (0.95 units/decade) than Insomnia (0.55 units/decade) group. Perhaps there was no correlation between age and SRM (r=0.07, n.s.) in the Healthy Older group due to the small age range, although this group did have a higher overall SRM score than the other two groups (p<0.01). The study thus confirmed that the previously observed increase in lifestyle regularity over the adult lifespan persists into later life. This may represent an adaptive behavioral response that might be used in future therapeutic approaches.  相似文献   

12.
Abstract

A comparison of intra‐ and inter‐ethnic divorce rates in Hawaii showed that inter‐ethnic marriages resulted in a higher proportion of divorces than did intra‐ethnic marriages when the marriage data used had to do with all marriages occurring in Hawaii. However, a sizeable portion of marriages in Hawaii are of nonresidents who, if they divorce, probably divorce elsewhere. Nonresident marriages are chiefly intra‐ethnic marriages of Caucasians. When examining the proportions of divorces to resident marriages, within‐group marriages are more at risk than inter‐ethnic marriages. As in prior research, persons who marry members of other racial/ethnic groups tend to marry persons from groups with income levels similar to their own. As in previous reports, some cross‐ethnic combinations appeared more at risk for divorce than did others. Group income appeared to be a predictor of risk. When considering only resident marriages as related to divorces, those marriages in which the bride was from a higher income group than the groom were at a significantly greater risk for divorce than marriage in which the bride came from an income group lower than that of the groom.  相似文献   

13.
14.
The complement system is an essential element of the innate immune response that becomes activated upon recognition of molecular patterns associated with microorganisms, abnormal host cells, and modified molecules in the extracellular environment. The resulting proteolytic cascade tags the complement activator for elimination and elicits a pro‐inflammatory response leading to recruitment and activation of immune cells from both the innate and adaptive branches of the immune system. Through these activities, complement functions in the first line of defense against pathogens but also contributes significantly to the maintenance of homeostasis and prevention of autoimmunity. Activation of complement and the subsequent biological responses occur primarily in the extracellular environment. However, recent studies have demonstrated autocrine signaling by complement activation in intracellular vesicles, while the presence of a cytoplasmic receptor serves to detect complement‐opsonized intracellular pathogens. Furthermore, breakthroughs in both functional and structural studies now make it possible to describe many of the intricate molecular mechanisms underlying complement activation and the subsequent downstream events, as well as its cross talk with, for example, signaling pathways, the coagulation system, and adaptive immunity. We present an integrated and updated view of complement based on structural and functional data and describe the new roles attributed to complement. Finally, we discuss how the structural and mechanistic understanding of the complement system rationalizes the genetic defects conferring uncontrolled activation or other undesirable effects of complement.  相似文献   

15.
Abstract

Studies of infant and child mortality have evolved to distinguish between two sets of explanatory variables—factors related to reproductive or maternal characteristics and socioeconomic factors, generally described as characteristics of the family or household. Almost all multivariate analyses include variables from each of these two sets, but there has been little consideration of the relationship between them. We examine how these two sets of variables jointly affect mortality. We test first for confounded effects by examining socioeconomic effects while excluding and then including reproductive variables in nested multivariate models. Next, we look for age‐dependent effects among the explanatory variables and find that reproductive and socioeconomic factors affect mortality at differing ages of children. Finally, we examine interactive effects of the two sets of variables. We conclude that the higher mortality observed among the low status groups is not a result of greater concentration of poor reproductive patterns in those groups. Instead, higher status groups probably have more resources available for combating the negative effects of the same high‐risk reproductive patterns.  相似文献   

16.
Neil Bissondath, SELLING ILLUSIONS: THE CULT OF MULTI‐CULTURALISM IN CANADA, Toronto: Penguin Books Canada, 1994, 234 pp., $16.99 (paper).

David A. Hollinger, POSTETHNIC AMERICA: BEYOND MULTI‐CULTURALISM, New York: Basic Books, 1995, 210 pp., $22.00

Will Kymlicka, MULTICULTURAL CITIZENSHIP, Oxford: Oxford University Press, 1995, 280 pp., npl.

Yasemin Nuhoglu Soysal, LIMITS OF CITIZENSHIP: MIGRANTS AND POSTNATIONAL MEMBERSHIP IN EUROPE, Chicago: Chicago University Press, 1994 (paper), npl.  相似文献   

17.
Genes located within the major histocompatibility complex (MHC) of mice are responsible for individual differences in body odor (odortypes). In this review we suggest that the MHC genes themselves are responsible for odor differences among MHC‐congenic mice. Recent studies indicating that volatile carboxylic acids are at least in part responsible for the individual odors and what this finding implies about the pathway from gene to odorant are also reviewed. We suggest that odorants or their precursors are bound directly by MHC products and are released into serum and concentrated in urine. Finally, possible functions of MHC odortypes in mice are enumerated and important future research questions are raised. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
ObjectivesTraumatic dental injury is defined as trauma caused by forces on a tooth with variable extent and severity. The aim of the present study was to investigate the prevalence of traumatic dental injury and its association with overjet, lip protection, sex, socioeconomic status, social capital and binge drinking among 12-year-old students.ResultsThe prevalence of traumatic dental injury was 29.9% (176/588). Traumatic dental injury was more prevalent among male adolescents (p = 0.010), those with overjet greater than 5 mm (p < 0.001) and those with inadequate lip protection (p < 0.001). In the multiple logistic regression analysis, overjet [OR = 3.80 (95% CI: 2.235–6.466), p < 0.0001], inadequate lip protection [OR = 5.585 (95% CI: 3.654–8.535), p < 0.0001] and binge drinking [OR = 1.93 (95% CI: 1.21–3.06), p = 0.005] remained significantly associated with traumatic dental injury.ConclusionsThe present findings suggest that a high level of total social capital and trust are not associated with TDI in adolescents, unlike binge drinking. The effects of social and behavioral factors on TDI are not well elucidated. Therefore, further research involving other populations and a longitudinal design is recommended.  相似文献   

19.
Abstract

The relationships between length of the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, pregnancy order, maternal age, and maternal history of previous child deaths and neonatal and postneonatal mortality were explored in a rural Bangladeshi population using a multiple regression analysis. Specific interactions between the interpregnancy interval, outcome of the pregnancy preceding the interval, sex of the infants, and history of previous child deaths were examined. An inverse relationship was observed between postneonatal mortality and the length of the interpregnancy interval when the pregnancy preceding the interval was a surviving infant. No such trend was observed for neonatal mortality. Post‐neonatal mortality rates among children whose mothers had experienced two or more previous child deaths were essentially the same as that for infants whose mothers had experienced 0–1 child deaths when the interpregnancy intervals were more than 24 months. Although female infants have a lower neonatal mortality than male infants, the neonatal mortality rate for female infants conceived less than twelve months following a male infant birth was higher than for a male infant conceived less than twelve months following another male infant birth. Post‐neonatal mortality is consistently higher for female compared to male infants in all interval categories.  相似文献   

20.
Synthesis of pyrimidine derivatives with a side‐chain attached to the C‐6 of pyrimidine ring (6–14) is reported. Target compounds 8 and 12 were subjected to in vitro phosphorylation tests, determination of their binding affinities to herpes simplex virus (HSV‐1) thymidine kinase (TK) and catalytic turnover constants. Fluorinated pyrimidine derivative 12 (40 µM) exhibited better binding affinity for HSV‐1 TK than acyclovir (ACV, 170 µM) and ganciclovir (GCV, 48 µM). Catalytic turnover constant (k cat) of 12 (0.08 s? 1) was close to the k cat values of ACV (0.10 s? 1) and GCV (0.10 s? 1). Furthermore, compounds 8 and 12 showed no cytotoxic effects in HSV‐1 TK‐transduced and non‐transduced cell lines. Besides, compounds 8 and 12 did not exhibit antiviral or cytostatic activities against several viruses and malignant tumor cell lines that were evaluated. The new fluorinated pyrimidine derivative 16 that is phosphorylated by HSV‐1 TK could be developed as non‐toxic PET‐tracer molecule. Thus, 18F labelling of the precursor 14 was performed by nucleophilic substitution using [18F] tetrabutylammonium fluoride as the fluorinating reagent.  相似文献   

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