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51.
The 2006 Nobel Prize in Physiology or Medicine was awarded to Andrew Fire and Craig Mello for discovering “RNA interference—genesilencing
by double-stranded RNA”. The Nobel Committee at the Karolinska Institute in Sweden selected them for the award for unraveling
“a fundamental mechanism for controlling the flow of genetic information” that is “already being widely used in basic science
as a method to study the function of genes and may lead to novel therapies in the future”. This has been one of the fastest
Nobel Prizes conferred in physiology or medicine, considering that Fire and Mello published their path-breaking article in
the journal Nature in 1998, less than ten years ago.
Utpal Nath is an Assistant Professor in the Department of Microbiology and Cell Biology, IISc. His laboratory is studying
the genetic mechanisms of plant development.
Saumitra Das is an Associate Professor in the Department of Microbiology and Cell Biology, IISc. His laboratory is interested
in the translational control of cellular and viral RNA. 相似文献
52.
53.
Sanju Jalla Sunil Sazawal Salkat Deb robert E. Black Satya Narayan Das Archana Sarkar Maharaj K. Bhan 《Indian journal of clinical biochemistry : IJCB》2004,19(2):95-99
Lymphocyte subset estimations by flow cytometry in population-based studies require transportation of samples from the field
site to the laboratory. As samples arrive late in the day they have to wait overnight before being processed. The effect of
two possible approaches, sample storage for 24 h before staining and immediate staining with analysis after 24 h and 48 h
were evaluated. Two sets of experiments were performed with EDTA (ethylenediamine tetra-acetate) anticoagulated peripheral
blood. In the first experiment, after collection, each sample was divided into two portions. One portion was stained at the
time of blood collection and the other 24 h later after keeping it at room temperature (38–45°C). In the second experiment,
blood samples were stained within 1–2 h. Each sample was analyzed immediately upon completion of staining process and subsequently
after 24 h and 48 h of storage at 4°C. Results suggest that blood collected in EDTA can be processed using whole blood lysis
method, after storage at room temperature (38–45°C) for 24 h with some but not significant alteration in T-cell subsets. Storage
at 4°C after staining for 24 h results in a lesser and insignificant loss of cells or alteration of T-cell subsets and may
be the method of choice. 相似文献
54.
Subir Kumar Das Prasunpriya Nayak D. M. Vasudevan 《Indian journal of clinical biochemistry : IJCB》2003,18(2):111-118
A variety of laboratory tests are available to assist in the diagnosis of alcohol consumption and related disorders. The levels
of intake at which laboratory results become abnormal vary from person to person. Laboratory tests are particularly useful
in settings where cooperativeness is suspected or when a history is not available. Several biochemical and hematological tests,
such as γ-glutamyltransferase (GGT) activity, aspartate aminotransferase (AST) activity, high-density lipoprotein cholesterol
(HDL-C) content of serum, and erythrocyte mean corpuscular volume (MCV) are established markers of alcohol intake. Their validity
as markers is based largely on correlations with recent intake at a single time point and on decreases in elevated values
when heavy drinkers abstain from alcohol. These readily available laboratory tests provide important prognostic information
and should be integral part of the assessment of persons with hazardous alcohol consumption. There are several other markers
with considerable potential for more accurate reflection of recent alcohol intake. These include carbohydrate deficient transferrin,
β-hexosaminidase, acetaldehyde adducts and the urinary ratio of serotonin metabolites, 5-hydroxytryptophol and 5-hydroxyindoleacetic
acid. These markers provide hope for more sensitive and specific aids to diagnosis and improved monitoring for intake. 相似文献
55.
Carbohydrate deficient transferrin (CDT) is one of the conventional markers for chronic alcohol consumption, is used by researchers
and clinicians. A number of enzymes are affected by ethanol intake. The induction or inhibition of sialyl transferase and
plasma sialidase may be involved in the CDT level elevation. An alteration of protein transport during post-translational
modification could be a primary mechanism in the impairment of protein metabolism associated with chronic alcohol abuse. Transferrin
being a steroid responsive protein, sex-based hormonal variations might contribute to the lower sensitivity of CDT. Varying
hormonal statuses such as pregnancy, use of contraceptives, menopause/ menstrual cycle can alter iron homeostasis in women.
CDT levels are markedly affected by iron homeostasis. Several CDT assay methods appeared promising, but it is not readily
apparent which technique is the most accurate. Moreover, false-positive results of CDT have been reported in non-alcohol related
hepatic failure and in rare conditions. Therefore clinical interpretation of CDT needs careful assessment in patients with
alcohol-related or non-alcohol-related health disorders. 相似文献
56.
Parsunpriya Nayak Subir Kumar Das D. M. Vasudevan 《Indian journal of clinical biochemistry : IJCB》2006,21(2):53-57
Aluminum and alcohol, both are well-accepted neurotoxin. The plausible mechanisms for their neurotoxicity are also common.
Therefore, the effect of ethanol on aluminum induced biochemical changes in rat brain is being studied. In the present study,
ethanol exposure significantly affected the aluminum and protein content of brain. The activities of acid phosphatase and
alkaline phosphatase were also changed. Aluminum exposure, on the other hand, contributed significantly in the alterations
of aluminum content, acid phosphatase acivity and aspartate aminotransferase activity. Though ethanol co-exposure significantly
influenced the aluminum load of brain, the interactions of these two neurotoxins were found to be significant only in case
of acid phosphatase activity of brain. Therefore, it can be suggested that general neurotoxicity produced by aluminum is not
modified by ethanol. However, the aluminum load caused by aluminum exposure, may be influenced by ethanol co-exposure. 相似文献
57.
Ranjana Singh Rajesh K. Singh Anil K. Tripathi Nikhil Gupta Ajai Kumar Anil K. Singh Abbas A. Mahdi Rajendra Prasad Raj K. Singh 《Indian journal of clinical biochemistry : IJCB》2004,19(1):14-20
The circadian periodicity of plasma lipid peroxide levels and activities of superoxide dismutase (SOD), catalase (CAT) and
glutathione peroxidase (GPx) were studied in 50 clinically, bacteriologically and radiologically proven fresh cases of pulmonary
tuberculosis (age: 21–45 years) and 60 age-matched healthy volunteers with diurnal activity from 06∶00 to about 22∶00 and
nocturnal rest. A marked circadian variation in plasma lipid peroxide level was recorded in healthy subjects and pulmonary
tuberculosis patients with significant amplitude and acrophase around 16∶21 and 17∶12 respectively. The acrophase tended to
be delayed in tuberculosis patients. Furthermore, a statistically significant circadian rhythm was found in SOD, CAT and GPx
activities in normal volunteers and pulmonary tuberculopsis patients. SOD and CAT enzyme activity was noted to be maximum
at 06∶00 and minimum at 00∶00 in tuberculosis patients. The circadian acrophase for GPx activity was recorded at 16∶15 in
normals and around 22∶45 in patients. Moreover, the activity was found to be decreased at all sampling hours during 24-hours
sleep-awake period in patients in comparison to healthy counterparts. The MESOR and circadian amplitude also decreased markedly.
The decreased activity of measured antioxidant enzymes in pulmonary tuberculosis patients could probably be associated with
oxidative stress and/or decreased anti-oxidant defensive mechanism in such patients. 相似文献
58.
59.
Subir Kumar Das Hiran K. R. Sukhes Mukherjee D. M. Vasudevan 《Indian journal of clinical biochemistry : IJCB》2007,22(1):99-104
Damaging effects of reactive oxygen species on living systems are well documented. They include oxidative attack on vital
cell constituents. Chronic ethanol administration is able to induce an oxidative stress in the central nervous system. In
the present study, 16–18 week-old male albino rats of Wistar strain were exposed to different concentration of ethanol for
4 weeks. This exposure showed profound effect on body weight. Ascorbic acid level; and activities of alkaline phosphatase
and aspartate transaminase in the brain are dependent on the concentration of ethanol exposure. Chronic ethanol ingestion
elicits statistically significant increase in thiobarbituric acid reactive substances level and decrease in gluatathione level
in the brain. It reduces superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities in a
dose dependent manner. However, histological examination could not reveal any pathophysiological changes. Therefore, we conclude
that biochemical alterations and oxidative stress related parameters respond early in alcoholism than the histopathological
changes in brain. 相似文献
60.
Santosh C. Das Aminu Z. Mohammed Sani U. Al-Hassan Abraham A. Otokwula Uche P. Isichei 《Indian journal of clinical biochemistry : IJCB》2007,22(2):79-83
In order to see the pattern of changes in differential serum lipid and lipoprotein fractions as a risk marker of coronary
complication in paired ‘maternal—neonate’ blood samples in an iodine deficient zone, 26 pregnant women and their corresponding
new born infants at term delivery from the iodine deficient Bassa region of Plateau state, Nigeria were assessed and the results
were compared with those seen in a similar 44 group of women and their newborns assessed in non lodine deficient region of
Jos. The serum thyroid function and lipid and lipoprotein profiles were determined by ‘ELISA’ and ‘enzymatic’ methods respectively.
Urinary iodide excretion level was also measured in 14 pregnant women in Bassa, 23 pregnant women in Jos and 16 non pregnant
control from Jos. Results indicate that the pregnant women assessed in Bassa were iodine deficient (P<0.01) and their thyroid
status was strikingly reduced as reflected by a drop in serum level of T4/TBG ratio (P<0.01) and a rise in TSH (P<0.005) in
comparison to that seen in Jos. There was marked hypertriglyceridaemia and total hypercholesterolaemia (P<0.005), with differential
significant rise in LDL cholestotol fraction (P<0.005) in the women assessed in Bassa as compared to Jos. The HDL cholesterol
however dropped less significantly in the group (P<0.05) with a concurrent marked rise (P<0.001) in the serum ratio of LDL
cholesterol/HDL cholesterol, total cholesterol/HDL cholesterol and triglycerides/HDL cholesterol in the lodine deficient group.
A similar pattern of changes were seen in the corresponding neonates in the Bassa group as compared to Jos group. It is concluded
that the pregnant women and their newborn offsprings living in a longstanding environmental iodine deficiency run a higher
risk of developing coronary complications than those living in non endemic region. It is striking that such newborns surrounded
by a continued state of lodine deficient may at a later adult-period of life develop marked risk of coronary complication
and other features of hyperlipidaemias associated with varying thyroid insufficiency and accompanied iodine deficiency disorders.
Prophylaxis measures as intervention has been highlighted. 相似文献