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1.
Gora Dadheech Sandhya Mishra Shiv Gautam Praveen Sharma 《Indian journal of clinical biochemistry : IJCB》2006,21(2):34-38
A disturbance in the antioxidant defense system including α-tocopherol, ascorbic acid and reduced glutahtione metabolism due
to free radical induced oxidative injury has been implicated in various neuro-psychiatric disorders. The roles of these antioxidants,
changes in their blood levels and correlation with oxidative stress were studied in a common psychiatric illness Schizophrenia.
Fifty-eight subjects of either sex ranging in age from 18–60 years divided into two age groups (≤40 and >40 years) diagnosed
for schizophrenia, and forty age and sex-matched normal subjects as controls were included in the study. Blood samples were
analyzed for malondialdehyde (MDA), α-tocopherol, total ascorbic acid (TAA), dehydro ascorbic acid (DHAA), reduced ascorbic
acid (RAA), leucocyte ascorbic acid (LAA) and reduced glutathione (GSH). A decrease in the levels of α-tocopherol, total ascorbic
acid and reduced glutathione was found in schizophrenics compared to normal controls. Further a significant rise in oxidative
stress and decreased antioxidant status was observed in the chronic stage of schizophrenia as compared to those in acute condition.
A significant rise in dehydroascorbic acid with concomitant fall in reduced ascorbic acid suggests scavenging action of ascorbic
acid and its utilization with increased oxidative stress as indicated by high blood malondialdehyde levels. Leucocyte ascorbic
acid, a better index of ascorbic acid status was also found to be reduced in schizophrenics, suggesting depletion of body
stores of ascorbic acid and the condition worsened with advancing age. 相似文献
2.
An assessment is offered of the recent debate on informationin the philosophy of biology, and an analysis is provided ofthe notion of information as applied in scientific practicein molecular genetics. In particular, this paper deals withthe dependence of basic generalizations of molecular biology,above all the ‘central dogma’, on the so-called‘informational talk’ (Maynard Smith [2000a]). Itis argued that talk of information in the ‘central dogma’can be reduced to causal claims. In that respect, the primaryaim of the paper is to consider a solution to the major difficultyof the causal interpretation of genetic information: how todistinguish the privileged causal role assigned to nucleic acids,DNA in particular, in the processes of replication and proteinproduction. A close reading is proposed of Francis H. C. Crick'sOn Protein Synthesis (1958) and related works, to which we owethe first explicit definition of information within the scientificpractice of molecular biology.
- Introduction
- 1.1 The basicquestions of the information debate
- 1.2 Thecausal interpretation(CI) of biological informationand Crick's‘central dogma’
- 1.1 The basicquestions of the information debate
- Crick's definitions of genetic information
- The main requirementfor (CI)
- Types of causation in molecular biology
- 4.1 Structuralcausation in molecular biology
- 4.2 Nucleicacids as correlativecausal factors
- 4.1 Structuralcausation in molecular biology
- The ‘central dogma’ withoutthe notion of information
- Concluding remarks
3.
部分初中学生用汉语的思维来理解和学习英语,对英汉两种语言差异了解不够,对系动词和实义动词的区别和用法混沌不清,从而导致他们容易犯系动词和实义动词不当混用的错误,这影响了他们英语学习成绩的提高,不利于其英语思维的培养。基于此,本文对此类错误进行分析,使学生加深对英汉两种语言的差异和相关英语语法规则的了解,按照英语的语言规则做出正确的表达。教师可以通过对语法的讲解和反复的练习来提升学生的语言规则意识,调动学生的积极情感,提高学生的认知能力,促使学生英语的语言习惯和能力在自然过程中形成。 相似文献
4.
Stephanie Patridge 《Ethics and Information Technology》2011,13(4):303-312
In this paper, I consider a particular amoralist challenge against those who would morally criticize our single-player video
play, viz., “come on, it’s only a game!” The amoralist challenge with which I engage gains strength from two facts: the activities
to which the amoralist lays claim are only those that do not involve interactions with other rational or sentient creatures,
and the amoralist concedes that there may be extrinsic, consequentialist considerations that support legitimate moral criticisms.
I argue that the amoralist is mistaken and that there are non-consequentialist resources for morally evaluating our single-player
game play. On my view, some video games contain details that anyone who has a proper understanding of and is properly sensitive
to features of a shared moral reality will see as having an incorrigible social meaning that targets groups of individuals,
e.g., women and minorities. I offer arguments to support the claim that there are such incorrigible social meanings and that
they constrain the imaginative world so that challenges like “it’s only a game” lose their credibility. I also argue that
our responses to such meanings bear on evaluations of our character, and in light of this fact video game designers have a
duty to understand and work against the meanings of such imagery. 相似文献
5.
The excessive generation of reactive oxygen species (ROS) by abnormal spermatozoa and contaminating leukocytes has been defined
as one of the few etiologies for male infertility. Administration of antioxidants in patients with ‘male factor’ infertility
has begun to attract considerable interest. The main difficulty of such an approach is our incomplete understanding of the
role of free radicals in normal and abnormal sperm function leading to male infertility. Mammalian spermatozoa membranes are
very sensitive to free radical induced damage mediated by lipid peroxidation, as they are rich in polyunsaturated fatty acids.
Limited endogenous mechanisms exist to reverse these damages. ROS attacks the fluidity of the sperm plasma membrane and the
integrity of DNA in the sperm nucleus. ROS induced DNA damage accelerate the germ cell apoptosis. Unfortunately spermatozoa
are unable to repair the damage induced by excessive ROS as they lack the cytoplasmic enzymes required to accomplish the repair.
Assessment of such oxidative stress status (OSS) may help in the medical treatment. Treatment strategies must be directed
toward lowering of ROS levels to keep only a small amount necessary to maintain normal cell function. 相似文献
6.
Hedgecoe A 《Social studies of science》2001,31(6):875-911
In this paper I explore the way in which scientists attempt to construct schizophrenia as a genetic disease using various discursive strategies. These strategies involve: referring back to earlier twin and adoption studies on schizophrenia inheritance; constructing genetic models to allow some r?le for single gene versions of the condition; a cautious and responsible limit on the strength of current research; and the construction of a range of bordering conditions which contribute to the genetic risk of schizophrenia. These various rhetorics produce a 'narrative' about schizophrenia which subtly prioritizes genetic explanations, while appearing to allow a r?le for non-genetic factors; I term this the 'narrative of enlightened geneticization'. This research has implications for scientific controversies, specifically the way in which critics attack schizophrenia genetics, since many of their points are already incorporated into the narrative. It also contributes to the ongoing debate over the r?le of social science research in the study of geneticization. 相似文献
7.
Knowledge of intrinsic wettability at solid/liquid interfaces at the molecular level perspective is significant in understanding crucial progress in some fields, such as electrochemistry, molecular biology and earth science. It is generally believed that surface wettability is determined by the surface chemical component and surface topography. However, when taking molecular structures and interactions into consideration, many intriguing phenomena would enrich or even redress our understanding of surface wettability. From the perspective of interfacial water molecule structures, here, we discovered that the intrinsic wettability of crystal metal oxide is not only dependent on the chemical components but also critically dependent on the crystal faces. For example, the crystal face of α-Al2O3 is intrinsically hydrophobic with a water contact angle near 90°, while another three crystal faces are intrinsically hydrophilic with water contact angles <65°. Based on surface energy analysis, it is found that the total surface energy, polar component and Lewis base portion of the hydrophobic crystal face are all smaller than the other three hydrophilic crystal faces indicating that they have different surface states. DFT simulation further revealed that the adsorbed interfacial water molecules on each crystal face hold various orientations. Herein, the third crucial factor for surface wettability from the perspective of the molecular level is presented, that is the orientations of adsorbed interfacial water molecules apart from the macro-level chemical component and surface topography. This study may serve as a source of inspiration for improving wetting theoretical models and designing controllable wettability at the molecular/atomic level. 相似文献
8.
9.
Xianlin Zeng Qing Hui Wassim M. Haddad Tomohisa Hayakawa James M. Bailey 《Journal of The Franklin Institute》2014
With advances in biochemistry, molecular biology, and neurochemistry there has been impressive progress in the understanding of the molecular properties of anesthetic agents. However, despite these advances, we still do not understand how anesthetic agents affect the properties of neurons that translate into the induction of general anesthesia at the macroscopic level. There is extensive experimental verification that collections of neurons may function as oscillators and the synchronization of oscillators may play a key role in the transmission of information within the central nervous system. This may be particularly relevant to understand the mechanism of action for general anesthesia. In this paper, we develop a stochastic synaptic drive firing rate model for an excitatory and inhibitory cortical neuronal network in the face of system time delays and stochastic input disturbances. In addition, we provide sufficient conditions for global asymptotic and exponential mean-square synchronization for this model. 相似文献
10.
We argue that the notion of trust, as it figures in an ethical context, can be illuminated by examining research in artificial
intelligence on multi-agent systems in which commitment and trust are modeled. We begin with an analysis of a philosophical
model of trust based on Richard Holton’s interpretation of P. F. Strawson’s writings on freedom and resentment, and we show
why this account of trust is difficult to extend to artificial agents (AAs) as well as to other non-human entities. We then
examine Margaret Urban Walker’s notions of “default trust” and “default, diffuse trust” to see how these concepts can inform
our analysis of trust in the context of AAs. In the final section, we show how ethicists can improve their understanding of
important features in the trust relationship by examining data resulting from a classic experiment involving AAs. 相似文献
11.
Katja de Vries 《Ethics and Information Technology》2010,12(1):71-85
The tendency towards an increasing integration of the informational web into our daily physical world (in particular in so-called
Ambient Intelligent technologies which combine ideas derived from the field of Ubiquitous Computing, Intelligent User Interfaces and Ubiquitous
Communication) is likely to make the development of successful profiling and personalization algorithms, like the ones currently
used by internet companies such as Amazon, even more important than it is today. I argue that the way in which we experience ourselves necessarily goes through a moment
of technical mediation. Because of this algorithmic profiling that thrives on continuous reconfiguration of identification
should not be understood as a supplementary process which maps a pre-established identity that exists independently from the
profiling practice. In order to clarify how the experience of one’s identity can become affected by such machine-profiling
a theoretical exploration of identity is made (including Agamben’s understanding of an apparatus, Ricoeur’s distinction between idem- and ipse-identity, and Stiegler’s notion of a conjunctive–disjunctive relationship towards retentional apparatuses). Although it is clear that no specific predictions about the impact of Ambient Intelligent technologies can be made without
taking more particulars into account, the theoretical concepts are used to describe three general scenarios about the way
wherein the experience of identity might become affected. To conclude, I argue that the experience of one’s identity may affect
whether the cases of unwarranted discrimination resulting from ubiquitous differentiations and identifications within an Ambient
Intelligent environment, will become a matter of societal concern. 相似文献
12.
H. Ravikumar K. S. Devaraju K. Taranath Shetty 《Indian journal of clinical biochemistry : IJCB》2008,23(2):117-122
Currently available method(s) for assaying pyrroline-5-carboxylate (P5C), an important intermediate metabolite of ornithine,
proline and glutamate metabolic pathways, are cumbersome or not sensitive enough for microanalysis. The present study involving
the synthesis of P5C followed by purity check, molecular mass (amu =113.1) determination by mass spectrometry and spectral
characterization of P5C-ninhydrin derivative (λ max: 510 nm) confirmed the authenticity of the preparation. Studies on the
effect of pH on spectral characteristics of P5C ninhydrin derivative demonstrated a significant change with respect to λ max
(620 nm) and several ∼ 12 fold increase in molar extinction coefficient (ε: 1.96 × 105) in alkaline conditions (pH:7.0–8.0) as compared to the reported Molar ε of 1.65 × 104 at max λ 510 nm in ethanolic solution. The modified method, with the improved sensitivity, is adopted for the assay of ornithine
amino transferase activity in WBC’s/platelets lysate(s) from human blood. 相似文献
13.
Rukmini M. S. Benedicta D'Souza Vivian D'Souza 《Indian journal of clinical biochemistry : IJCB》2004,19(2):114-118
Free radical mediated pathological processes may have a role in schizophrenia. Free radicals (oxy radicals, such as superoxide,
hydroxyl ions and nitric oxide) cause cell injury, when they are generated in excess or when the antioxidant defense is impaired.
Both these processes seem to be affected in schizophrenia. In this study we investigated erythrocyte superoxide dismutase
(SOD) and catalase (CAT) activities as antioxidant enzymes, malondialdehyde (MDA) as a sign of lipid peroxidation in schizophrenic
patients. Activities of superoxide dismutase, catalase and malondialdehyde were greater in patients compared with the control
group which may reflect increased oxidative stress in the brain tissue of schizophrenics. In the patient group erythrocyte
SOD and CAT activities were weakly negative correlated with MDA concentration. These data reveal that antioxidant defense
mechanisms might be impaired in schizophrenic patients. These findings also provide a theoretical basis for the development
of novel therapeutic strategies, such as antioxidant supplementation. 相似文献
14.
Rama D. Mittal Hemant K. Bid Parmeet K. Manchanda Rakesh Kapoor 《Indian journal of clinical biochemistry : IJCB》2008,23(2):106-116
Urolithiasis is a relevant clinical problem with a subsequent burden for health system. The aim of this review is to provide
recent progress made using genetic polymorphisms to define pathophysiology, to identify persons at risk for kidney stone disease
and to predict treatment response. Population case-control studies are useful both as an alternative and an adjunct as compared
to family studies. These involve either whole genome scanning or candidate gene approaches. While whole genome scanning is
likely to be widely used in future, at present, candidate gene studies are more feasible. When performing candidate gene case-control
studies factors such as study design, methods for recruitment of case and controls, selection of candidate genes, functional
significance of polymorphisms chosen for study and statistical analysis require close attention to ensure that only genuine
associations are detected. Some of the significant genes that play role in stone formation include calcitonin receptor gene
(CTR), vitamin D receptor (VDR), Urokinase, Interleukin, (IL-1β, IL-Ra), E-Cadherin, Androgen & oestrogen receptor gene, vascular
endothelial growth factor (VEGF) and Arginine p21. In our case-control study we studied CTR, VDR, Urokinase, IL-1β(−511 and
+3954), IL-Ra from north India and predict that VDR, IL-β (-511) and IL-1Ra gene may be used as a possible genetic marker
for earlier detection in patients who are at risk for calcium oxalate stone disease. Further, linkage disequilibrium and haplotype
structure of a certain candidate gene is important for association analysis. When a certain polymorphic allele has been found
to be associated with disease, it is further explained on basis of LD and haplotype structure by one or more other alleles.
Once it is determined which haplotype carries the risk allele, by means of molecular biological functional analyses, the variants
on that haplotype allele truly causing the effect can be determined. 相似文献
15.
Naotaka Hamasaki 《Indian journal of clinical biochemistry : IJCB》1999,14(1):49-58
The synergistic effects of hemoglobin, carbonic anhydrase and the band 3 protein make red blood cells the ideal vehicle for oxygen delivering to the tissues. As long as oxygen is supplied by these ideal vehicles, oxygen intoxication of the tissues is precluded. Band 3 protein mediates the “Chloride-Shift”, i.e., the anion exchange of Cl−/HCO3 −. Because of the Chloride-Shift, red blood cells are able to recognize metabolically active tissues and to supply the minimum amount of oxygen to the tissues. Investigation into the molecular mechanisms of the anion exchange mediated by the band 3 protein was introduced. 相似文献
16.
Developing artificial agents worthy of trust: “Would you buy a used car from this artificial agent?”
There is a growing literature on the concept of e-trust and on the feasibility and advisability of “trusting” artificial agents. In this paper we present an object-oriented model
for thinking about trust in both face-to-face and digitally mediated environments. We review important recent contributions
to this literature regarding e-trust in conjunction with presenting our model. We identify three important types of trust
interactions and examine trust from the perspective of a software developer. Too often, the primary focus of research in this area has been on the artificial agents and the humans they may encounter
after they are deployed. We contend that the humans who design, implement, and deploy the artificial agents are crucial to
any discussion of e-trust and to understanding the distinctions among the concepts of trust, e-trust and face-to-face trust. 相似文献
17.
D Tomar V Chattree V Tripathi A A Khan A R Bakshi D N Rao 《Indian journal of clinical biochemistry : IJCB》2005,20(1):213-230
The development of vaccines to prevent infectious diseases has been one of the most important contributions of biomedical
sciences. Increasing understanding in biochemistry, molecular biology, molecular genetics and related fields have provided
an opportunity for the development of new generation vaccines that are based on rational design approaches. This is possible
because of proper understanding of the microbial-genetics, biochemistry, host-pathogen interaction and recent developments
in molecular immunology. Another important improvement made in the quality of vaccine production is the incorporation of immunomodulators
or adjuvants with modified delivery vehicles viz liposomes, Iscoms and microspheres apart from alum being used as a gold standard.
This article reviews the art of vaccination from Jenner period to present day context highlighting all the developments made
at each stage of the vaccine development. Various criteria have been discussed regarding the selection of epitopes that expand
B & T cells, its linkage with other accessory cells of the immune system, means to overcome MHC linked immune unresponsiveness,
enhanced antigen processing and presentations that specially induce either helper or cytotoxic or mucosal immune responses
were critically discussed. 相似文献
18.
Santoshi R. Ghodake A. N. Suryakar R. D. Ankush K. Shaikh A. V. Katta 《Indian journal of clinical biochemistry : IJCB》2010,25(1):82-85
Nephrotic syndrome is the common chronic disorder characterized by alteration of permeability of the glomerular capillary
wall, resulting in its inability to restrict the urinary loss of proteins. Nephrotic syndrome is characterized by heavy proteinuria,
hypoalbuminemia, hyperlipidemia associated with peripheral edema. The molecular basis of glomerular permselectivity remains
largely unknown. In recent years it has been proposed that Nephrotic syndrome is a consequence of an imbalance between oxidant
and antioxidant activity. The present study was aimed to test that the reactive oxygen species are the mediators of excessive
protein permeability and other complications of Nephrotic syndrome. For this 30 adults with Nephrotic syndrome were studied.
The control group comprised 30 healthy adults matched for age. Serum levels of lipid peroxides, nitric oxide (NO⊙), α- tocopherol,
ascorbic acid, erythrocyte superoxide dismutase activity, serum albumin, uric acid, cholesterol and plasma total antioxidant
capacity were measured. Student’s ‘t’ test was applied for statistical analysis. There was a significant increase in lipid
peroxide (1.58 ± 0.42 in controls, 3.64 ±1.3 in patients) (P<0.001) levels in study group as compared with controls. α-tocopherol
(12.95 ± 1.04 in controls, 9.93 ± 1.43 in patients) (P<0.001), erythrocyte SOD activity(1.88 ± 0.9 in controls 1.07 ± 0.5
in patients) (P=0.01), serum albumin(4.06 ± 0.50 in controls, 3.04 ± 0.11 in patients) (P<0.001), and plasma total antioxidant
capacity (847.33 ± 126.83 in controls, 684.00±102.94 in patients) (P<0.001) were significantly decreased. There was non-significant
increase in uric acid (P>0.05), a non-significant decrease in NO⊙ (38.48 ± 15.47 in controls 37.47 ± 14.27 in patients) (P>0.05)
and ascorbic acid levels ascorbic acid,( 0.95 ± 0.31in controls 0.79 ± 0.30 in patients) (P>0.05) in study group as compared
with controls. Imbalance between oxidants and antioxidants may contribute to pathogenesis of proteinuria and related complications
in nephrotic syndrome. 相似文献
19.
K. Sri Krishna A. S. Kanagasabapathy 《Indian journal of clinical biochemistry : IJCB》1991,6(1):17-25
Little is known of conditions which influence the stability of urinary enzymes upon storage in the bladder at 37°C. Using
a continuous flow system simulatingin vivo conditions, we studied the influence of the pH of urine on the stability of two renal parenchymal enzymes N—Acetyl—β—D—Glucosaminidase
(2—acetamido—2—deoxy—β—D—glucoside acetamidodeoxy glucohydrolase, NAG, EC 3.2.1.30) and L—Alanine aminopeptidase (Aminopeptidase
N, AAP, EC 3.4.11.2). This continuous flow model that we have described can be employed to study the influence of pH on the
stability of any renal enzyme excreted in urine. We also studied thein vitro effects of varying concentrations of low molecular weight regulatory metabolites such as urea, creatinine and uric acid and
of some drugs excreted in urine, on the assay of these two enzymes. Urinary pH, urea content and some antibiotics seem to
influence measured urinary NAG and AAP activities and we therefore express the need for caution before diagnostic interpretation
of the urinary enzyme activities are made. 相似文献
20.
高效课堂教学模式的探究,以精心设置的问题引导学生展开讨论,打开知识的缺口,点燃学生智慧的火花,让学生明确每个知识的形成过程,增强学生对知识的理解。教学中以“问”引其疑、以“问”启其思、以“问”增其识,是一种行之有效的教学方法。 相似文献