33 results on '"Alka Shukla"'
Search Results
2. SARS-CoV-2 Transmission Risk through Expressed Breast Milk Feeding in Neonates Born to COVID 19 Positive Mothers: A Prospective Observational Study
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Akash Pandey, Alka Shukla, and Purushottam Lal
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breastfeeding ,covid 19 ,expressed breast milk ,lactation ,newborn ,sars-cov-2 ,Pediatrics ,RJ1-570 - Abstract
Background: Mother-to-child transmission of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) has become a matter of great concern in post-partum wards and neonatal units. With little prior experience of this novel infection, there are contradictory findings in the literature regarding breastfeeding androoming-in for newborns of mothers with COVID-19 disease. To assess the transmission risk of SARS-CoV- 2 in neonates who were fed expressed breast milk of COVID-19 positive mothers. Methods: This prospective study included 16 neonates born to COVID-19 positive mothers. The neonates were nursed in a neonatal unit separate from their mother. Expressed breast milk was fed by health care givers ensuring proper safety measures. Nasal and throat swabs of neonates were tested twice for SARS CoV-2, firstly, at 48 h of life and secondly, before discharge. Results: Pneumonia was present in 3 (20%) mothers, and C- reactive protein was raised in 9 (60 %) mothers. Birth weight was low in 8 (50%) neonates. Respiratory distress syndrome and meconium aspiration syndrome were present in two and one newborns, respectively. Nasal and throat swabs of all 16 newborns tested negative for SARS-CoV- 2 infection twice, at 48 h of life and before discharge. Conclusion: Expressed breast milk feeding can be considered safe in neonates born to COVID-19 positive mothers. Even sick mothers with COVID-19 can continue to express breast milk after ensuring proper safety measures.
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- 2021
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3. Developing an NIRS Prediction Model for Oil, Protein, Amino Acids and Fatty Acids in Amaranth and Buckwheat
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Shruti, Alka Shukla, Saman Saim Rahman, Poonam Suneja, Rashmi Yadav, Zakir Hussain, Rakesh Singh, Shiv Kumar Yadav, Jai Chand Rana, Sangita Yadav, and Rakesh Bhardwaj
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machine learning ,RSQ ,RPD ,mPLS ,WINISI ,validation ,Agriculture (General) ,S1-972 - Abstract
Amaranth and buckwheat are two pseudo-cereals preferred for their high nutritional value, are gluten free and carry religious importance as fasting food. Germplasm resources are the reservoir of diversity for different traits, including nutritional characteristics. These resources must be evaluated to utilize their potential in crop improvement programs. However, conventional methods are labor-, cost- and time-intensive and prone to handling errors when applied to large samples. NIRS-based machine learning to predict different nutritional traits is applied in different food crops for multiple traits. NIRS prediction models are developed in this study using the mPLS regression technique for oil, protein, fatty acids and essential amino acid estimation in amaranth and buckwheat. Good RSQ external (power of determination) values were obtained for the above traits ranging from 0.72 to 0.929. Ratio performance deviation (RPD) value for most of the traits ranged between 2 and 3, except for valine (1.88) and methionine (3.55), indicating good prediction capabilities in the developed model. These prediction models were utilized in screening the germplasm of amaranth and buckwheat; the results obtained were in good agreement and confirmed the applicability of developed models. It will enable the identification of a trait-specific germplasm as a potential gene source and aid in crop improvement programs.
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- 2023
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4. Vitality of Proteinase K in rRTPCR Detection of SARS-CoV2 Bypassing RNA Extraction
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Alka Shukla, Mayank Gangwar, Gaurav Sharma, Pradyot Prakash, and Gopal Nath
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real time PCR ,SARS-CoV-2 detection ,heat inactivation ,COVID – 19 ,Proteinase K ,Microbiology ,QR1-502 - Abstract
This study aimed to detect the SARS-COV2 viral component directly from inoculated VTM without RNA extraction. Inoculated VTMs of already tested 50 positive and 50 negative samples were divided into three groups. Group I was treated with Proteinase K (PK) followed by 3-step-heat treatment at different temperatures (25°C, 60°C, and 98°C) and stored at 4°C. Group II was directly subjected to 3-step-heat treatment without PK exposure and stored at 4°C. And group III was set-up as standard group; it was processed using Qiagen’s column based QIAamp Nucleic Acid kit and the obtained nucleic acids were stored at 4°C. These stored samples were used as a template to execute real-time polymerase chain reaction, and results were noted. Group I demonstrated 96% and 88% sensitivity for N and ORF1ab genes respectively, whereas group II demonstrated 78% and 60% when compared to the results of standard group III. Overall group I showed better results than group II when compared to group III. Thus, in situations where gold-standard reagents are not available, PK exposure and heat treatment can be employed to carry out molecular detection of SARS-CoV2 viral component.
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- 2021
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5. Viral Encephalitis: A Hard Nut to Crack
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Alka Shukla, Mayank Gangwar, Sonam Rastogi, and Gopal Nath
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encephalitis ,viral infection ,pathogenesis ,molecular techniques ,management ,General works ,R5-130.5 ,Science - Abstract
Viral encephalitis is inflammation of brain that manifests as neurological complication of viral infections. There are quite a good number of viruses, for example, human herpes virus, Japanese encephalitis, and enteroviruses that can result in such a dreadful condition. Geographical location, age, gender, immune status, and climatic conditions also contribute to the establishment of this disease in an individual. Clinical signs and symptoms include fever, headache, altered level of consciousness, changed mental status, body ache, seizures, nausea, and vomiting. Effective management of this disease relies on timely diagnosis that in turn depends on apt and suitable investigation techniques. Traditional investigations have thinned out these days owing to the fact that advanced molecular technologies have been introduced to the diagnostic field. Treatment of viral encephalitis mainly involves symptomatic relieve from fever, malaise, myalgia along with measures to reduce viral load in the patient. This review mentions about all the possible aspects of viral encephalitis starting from etiology to the management and preventive measures that include immunization and vector control.
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- 2019
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6. RETRACTED: Study on the Effect of Oral Administration of Bacteriophages in Charles Foster Rats With Special Reference to Immunological and Adverse Effects
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Mayank Gangwar, Sonam Rastogi, Digvijay Singh, Alka Shukla, Neeraj Dhameja, Deepak Kumar, Rajesh Kumar, and Gopal Nath
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oral ,adverse effect ,cytokines ,Klebsiella pneumoniae ,bacteriophage therapy ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Numerous pre-clinical and clinical studies have recently demonstrated the significant role of phage therapy in treating multidrug-resistant bacterial infections. However, only a few researchers have focused on monitoring the phage-mediated adverse reactions during phage therapy. Besides adverse reactions, immunological response after short- and long-term oral administration of bacteriophages is also lacking. In this study, we administered the bacteriophages orally against Klebsiella pneumoniae XDR strain in dosages of 1015 PFU/ml and a 1020 PFU/ml (still higher) to Charles Foster rats as a single dose (in acute toxicity study) and daily dosage for 28 days (in sub-acute toxicity study). One milliliter suspension of bacteriophages was administered through the oral gavage feeding tube. No adverse effect was observed in any of the experimental as well as in the control animals.Further, an insignificant change in food and water intake and body weight was observed throughout the study period compared with the control group rats. On the 28th day of phage administration, blood was collected to estimate hematological, biochemical, and cytokines parameters. The data suggested no difference in the hematological, biochemical, and cytokine profile compared to the control group. No significant change in any of the treatment groups could be observed on the gross and histopathological examinations. The cytokines estimated, interleukin-1 beta (IL-1β), IL-4, IL-6, and INF-gamma, were found within the normal range during the experiment. The results suggested no adverse effect, including the severe detrimental impact on oral administration of high (1015 PFU/ml) and very high dose (1020 PFU/ml) of the bacteriophages cocktail. The high and long-term oral administration of bacteriophages did not induce noticeable immunological response as well.
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- 2021
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7. Immunological and safety profile of bacteriophage therapy: A pre-clinical study
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Mayank Gangwar, Sonam Rastogi, Digvijay Singh, Alka Shukla, Neeraj Dhameja, Deepak Kumar, Rajesh Kumar, and Gopal Nath
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Klebsiella pneumoniae ,Drug Resistance, Multiple, Bacterial ,Animals ,Cytokines ,Bacteriophages ,Phage Therapy ,General Medicine ,Applied Microbiology and Biotechnology ,Rats ,Biotechnology - Abstract
Aims Numerous pre-clinical and clinical studies have recently demonstrated the significant role of phage therapy in treating multidrug-resistant bacterial infections. However, only a few researchers have focused on monitoring the phage-mediated adverse reactions during phage therapy. The present study aimed to demonstrated the oral acute and sub-acute toxicity of bacteriophages (Klebsiella pneumoniae XDR strain) in Charles Foster rats with special reference to immunological response and adverse effects. Methods and Results Bacteriophages were orally administered in dosages of 1010 PFU/ml and a 1015 PFU/ml to Charles Foster rats as a single dose (in acute toxicity study) and daily dosage for 28 days (in sub-acute toxicity study). One millilitre suspension of bacteriophages was administered through the oral gavage feeding tube. No adverse effect was observed in any of the experimental as well as in the control animals. Furthermore, an insignificant change in food and water intake and body weight was observed throughout the study period compared with the control group rats. On the 28th day of phage administration, blood was collected to estimate haematological, biochemical and cytokines parameters. The data suggested no difference in the haematological, biochemical and cytokine profiles compared to the control group. No significant change in any of the treatment groups could be observed on the gross and histopathological examinations. The cytokines estimated, interleukin-1 beta (IL-1β), IL-4, IL-6 and IFN-gamma, were found within the normal range during the experiment. Conclusions The results concluded that no adverse effect, including the severe detrimental impact on oral administration of high (1010 PFU/ml) and very high dose (1015 PFU/ml) of the bacteriophages cocktail. Significance and Impact of Study The high and long-term oral administration of bacteriophages did not induce noticeable immunological response as well.
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- 2022
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8. Epidemiological Distribution and Potential Risk Factors of Orientia tsutsugamushi Infection in Eastern Uttar Pradesh, India
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Mayank Gangwar, Deepak Kumar, Akanksha Srivastava, Alka Shukla, Digvijay Singh, Gopal Nath, Sonam Rastogi, Pradyot Prakash, and Rajesh Kumar
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medicine.medical_specialty ,Orientia tsutsugamushi ,biology ,Zoonotic Infection ,business.industry ,General Medicine ,Scrub typhus ,Disease ,bacterial infections and mycoses ,medicine.disease ,biology.organism_classification ,Disease Presentation ,Infectious disease (medical specialty) ,Environmental health ,Epidemiology ,medicine ,Rural area ,business - Abstract
Background: Scrub typhus (ST) is a rickettsial infection caused by Orientia tsutsugamushi, which presents with flu like symptoms. This disease has been reported from all over India but with slight variations in its pattern. For decreasing the prevalence, preventing new incidences, and predicting the course of the ST, therefore, it is crucial to gain knowledge and perception of local risk components associated with the disease. The present study aimed to investigate the epidemiological distribution and potential risk factors of O. tsutsugamushi Infection in Eastern Uttar Pradesh (EUP), India. Methods: The serums of 211 samples were collected from the suspected cases along with the detailed information about the participants such as age, location, and place recorded in case history form (CRF). IgM estimation was performed using enzyme-linked immunosorbent assay (ELISA) assay. Results: A total of 58 samples (27.4%) out of 211 ones were found to be positive for IgM antibodies against O. tsutsugamushi bacterium. Furthermore, the results were correlated with epidemiological data such as gender, rural or urban background, pets, and occupation. The results showed that 76.7% of the study participants were from rural areas or had bushes around their houses, 88.3% of them had pets/cattle or frequent encounter with rodents at their houses, and 30.3% of them had no toilet facilities at home. Conclusions: It was concluded that the proximity to pets/cattle, having rodents in closer vicinity, residing in places surrounded by vegetation/farm/bushy areas, and following occupations involving field work increased the chances of getting bitten by mites/chiggers. Overall, Orientia tsutsugamushi prevalence increased in EUP, with respect to clinical features, disease presentation, and laboratory diagnosis can help our community to reduce the mortality caused by this infectious disease.
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- 2021
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9. Comparative Evaluation of Efficacy of ProTaper® Universal Rotary Retreatment System for Gutta-percha Removal from Single Root Canals, Obturated with Two Different Techniques: In Vitro Cone-beam Computed Tomography Study
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Chittenahalli N Vijay Kumar, Krishna P Lashkari, Gaurav Sharma, and Alka Shukla
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Orthodontics ,Cone beam computed tomography ,Materials science ,biology ,General Medicine ,Gutta-percha ,biology.organism_classification ,Endodontic retreatment ,Comparative evaluation - Published
- 2019
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10. Assessment of Successful qRT-PCR of SARS-CoV-2 Assay in Pool Screening Using Isopropyl Alcohol Purification Step in RNA Extraction
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Alka Shukla, Mayank Gangwar, Gopal Nath, Virendra Kumar Patel, and Pradyot Prakash
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0301 basic medicine ,Article Subject ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,030106 microbiology ,Oropharynx ,Real-Time Polymerase Chain Reaction ,Sensitivity and Specificity ,General Biochemistry, Genetics and Molecular Biology ,2-Propanol ,03 medical and health sciences ,chemistry.chemical_compound ,Coronavirus Envelope Proteins ,0302 clinical medicine ,Nasopharynx ,Humans ,030212 general & internal medicine ,Gene ,DNA Primers ,Chromatography ,General Immunology and Microbiology ,Chemistry ,SARS-CoV-2 ,RNA ,COVID-19 ,Reproducibility of Results ,Isopropyl alcohol ,General Medicine ,Real-time polymerase chain reaction ,RNA, Viral ,Medicine ,RNA extraction ,Isopropyl ,Biomarkers ,Research Article - Abstract
The study is aimed at establishing the optimal parameters for RNA purification of pooled specimens, in SARS-CoV-2 assay. This research work evaluates the difference of extracted RNA purity of pooled samples with and without treatment with isopropyl alcohol and its effect on real-time RT-PCR. As per the protocol of the Indian Council of Medical Research (ICMR), 5 sample pools were analysed using qRT-PCR. A total of 100 pooled samples were selected for the study by mixing 50 μL of one COVID-19 positive nasopharyngeal/oropharyngeal (NP/OP) specimen and 50 μL each of 4 known negative specimens. Pool RNA was extracted using the column-based method, and 1 set of pooled extracted RNA was tested as such, while RNA of the second set was treated additionally with chilled isopropyl alcohol (modified protocol). Further, the purity of extracted RNA in both the groups was checked using Microvolume Spectrophotometers (Nanodrop) followed by RT-PCR targeting E-gene and RNaseP target. The results showed that the purity index of extracted RNA of untreated pooled specimens was inferior to isopropyl alcohol-treated templates, which was observed to be 85% sensitivity and 100% specificity. The average Cq (E gene) in the unpurified and purified pool RNA group was 34.66 and 31.48, respectively. The nanodrop data suggested that purified RNA concentration was significantly increased with an average value of 24.73 ± 1.49 ng / uL , which might be the reason for high sensitivity and specificity. Thus, this group testing of SARS-CoV-2 cases using pools of 5 individual samples would be the best alternative for saving molecular reagents, personnel time, and can increase the overall testing capacity. However, purity of RNA is one of the important determinants to procure unfailing results, thus, this additional purification step must be included in the protocol after RNA has been extracted using commercially available kit before performing qRT-PCR.
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- 2021
11. Extraction and Chemo profiling of Agaricus bisporus at Vindhya Region
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Alka Shukla, Deepak Mishra, and Virendra Kumar Pandey
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Chromatography ,Chemistry ,Agaricus bisporus - Published
- 2020
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12. Untapped amaranth (Amaranthus spp.) genetic diversity with potential for nutritional enhancement
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Poonam Suneja, Nidhi Srivastava, Sangita Yadav, Zakir Hussain, Alka Shukla, Shiv Kumar Yadav, and Jai Chand Rana
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0301 basic medicine ,chemistry.chemical_classification ,Genetic diversity ,030109 nutrition & dietetics ,Methionine ,biology ,Linoleic acid ,Fatty acid ,Amaranth ,04 agricultural and veterinary sciences ,Plant Science ,Amaranthus hypochondriacus ,biology.organism_classification ,040401 food science ,03 medical and health sciences ,chemistry.chemical_compound ,Oleic acid ,0404 agricultural biotechnology ,chemistry ,Genetic distance ,Botany ,Genetics ,Food science ,Agronomy and Crop Science ,Ecology, Evolution, Behavior and Systematics - Abstract
Significant genetic diversity was observed in 218 out of a total of 1309 accessions of amaranth (Amaranthus hypochondriacus L.) and its seven wild relatives, A. spinosus L., A. dubius Mart. ex Thell., A. hybridus L., A. tricolor L., A. cruentus L., A. caudatus L., A. retroflexus L. for 24 nutritional parameters including total oil content, fatty acid profile, total protein content and amino acid profile. Diversity for total oil content (6.42–12.53%), linoleic acid (25.68–54.34%), oleic acid (21.97–42.01%) of the total fatty acids, total protein content (7.84–18.01%), among important essential amino acids; lysine content (0.66–11.12 g/16 g N), methionine (0.35–4.80 g/16 g N) and half cystine and (0.12–8.32 g/16 g N) was reported. The un-weighted pair-group method using arithmetic average cluster analysis based on pair wise Euclidean genetic distance grouped the accessions into seven major clusters. Histidine, half cystine, tyrosine, essential amino acids, total oil content, linoleic acid and oleic acid content were the major parameters contributing significantly to genetic diversity. Present findings indicate that significant diversity exists for nutritional parameters in amaranth germplasm. The promising accessions with higher multiple nutritive traits; protein content (>16%), oil content (>11%), lysine content (>7.5 g/16 g N) and EAA higher than the FAO reported values, were identified. This is the first report on detailed nutritional analysis of diversity collected worldwide. These could be used as potential breeding material for nutritional enhancement through genetic improvement. This will help in overcoming the “triple burden” of malnourishment, hidden hunger, and obesity.
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- 2017
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13. Pancreatic acinar cell: New insights into the control of secretion
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Jiun T. Low, Alka Shukla, and Peter Thorn
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medicine.medical_specialty ,chemistry.chemical_element ,Biology ,Calcium ,Biochemistry ,Calcium in biology ,Exocytosis ,03 medical and health sciences ,0302 clinical medicine ,Pancreatic Juice ,Internal medicine ,medicine ,Acinar cell ,Animals ,Humans ,Secretion ,Calcium Signaling ,Pancreas ,030304 developmental biology ,0303 health sciences ,Secretory Pathway ,T-type calcium channel ,Epithelial Cells ,Cell Biology ,Enzymes ,Cell biology ,Calcium ATPase ,medicine.anatomical_structure ,Endocrinology ,Pancreatitis ,chemistry ,030220 oncology & carcinogenesis ,Digestion - Abstract
Pancreatic acinar cells secrete fluid and digestive enzymes. Both types of secretion are activated by a rise in intracellular calcium but how the stimulus-secretion cascade actually regulates secretory output is not well understood. It has long been known that the calcium response of acinar cells to physiological stimulation is complex. Dependent on the type and concentration of agonist, it consists of either local or global calcium increases as well as spreading waves of calcium across the cell. In the past it has been speculated that these different calcium signals drive different secretory responses. Now, recent employment of two-photon microscopy has enabled the simultaneous recording of both enzyme secretion and calcium signals and is beginning to resolve this issue. The data shows that local calcium responses exclusively drive fluid secretion. Where-as, global calcium responses drive both fluid and enzyme secretion. This differential control of secretory output is likely central to controlling the physiological responses of pancreatic acinar cells.
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- 2010
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14. Local dynamic changes in confined extracellular environments within organs
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Peter Thorn, Christof J. Schwiening, Alka Shukla, and Natasha Behrendorff
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medicine.medical_specialty ,Exocrine gland ,Physiology ,chemistry.chemical_element ,Lumen (anatomy) ,Environment ,Calcium ,Biology ,Models, Biological ,Exocytosis ,Exocrine Glands ,Live cell imaging ,Physiology (medical) ,Internal medicine ,medicine ,Extracellular ,Animals ,Humans ,Pharmacology ,Animal Structures ,Hydrogen-Ion Concentration ,Body Fluids ,Cell biology ,Kinetics ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Extracellular Space ,Pancreas ,Homeostasis - Abstract
1. Herein we review past work that has studied the composition of luminal fluid in organs, with a focus on measures of calcium and pH in the exocrine glands. This luminal environment is 'external' to the mammalian body and is not subject to the usual mechanisms of homeostatic control. Instead, it is controlled by the behaviour of the cells that line the lumen. 2. We discuss the likely possibility that rapid and local changes in calcium and pH occur within microdomains in the lumen. Further, we present preliminary evidence, using live cell imaging of intact pancreatic fragments, that supports the idea that pH changes do occur. Our evidence indicates that exocytosis of secretory granules in pancreatic acinar cells leads to a loss of protons from the granule and a subsequent local acidification of the lumen. 3. These changes in luminal composition are placed in the context of diseases of the pancreas, such as cystic fibrosis and pancreatitis, both of which are known to result in perturbations of luminal fluid composition.
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- 2009
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15. Wireless ethernet for IoT: A case study
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Akash Garg, Peeyush Chandra, Vandana Rathore, Alka Shukla, and Shikhar Bahl
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business.product_category ,business.industry ,Computer science ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,020206 networking & telecommunications ,02 engineering and technology ,Metro Ethernet ,Networking hardware ,Synchronous Ethernet ,Network interface controller ,0202 electrical engineering, electronic engineering, information engineering ,Network switch ,Fiber Distributed Data Interface ,business ,ATA over Ethernet ,Computer network ,Carrier Ethernet - Abstract
Wireless ethernet is one of the most important wireless technology that enhances our personal environment, either work or private, by means of networking or a variety of personal and wearable devices within the space and with the outside world. It refers to a link layer protocol in the TCP/IP (Transmission Control Protocol/Internet Protocol) stack, describing how networked devices can format data for transmission to other network devices on the same network segment, and how to put that data out on the network connection. This paper represents an overall view of the wireless Ethernet features, advantages, applications and integration of mobile communication. It initially assumed a shared medium: multiple devices on each segment of the network, connected daisy chain at first but later in star topology via Ethernethubs(which replicated all traffic received on any port to every other port).
- Published
- 2016
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16. Direct electrochemistry of human and rat NADPH cytochrome P450 reductase
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Paul V. Bernhardt, Alka Shukla, and Elizabeth M. J. Gillam
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Flavin adenine dinucleotide ,chemistry.chemical_classification ,biology ,Stereochemistry ,Cytochrome P450 reductase ,Cytochrome P450 ,Redox ,lcsh:Chemistry ,chemistry.chemical_compound ,Electron transfer ,chemistry ,lcsh:Industrial electrochemistry ,lcsh:QD1-999 ,Oxidoreductase ,Electrochemistry ,biology.protein ,Proton-coupled electron transfer ,Heme ,lcsh:TP250-261 - Abstract
The diflavo-protein NADPH cytochrome P450 reductase (CPR) is the key electron transfer partner for all drug metabolizing cytochrome P450 enzymes in humans. The protein delivers, consecutively, two electrons to the heme active site of the P450 in a carefully orchestrated process which ultimately leads to the generation of a high valent oxo-heme moiety. Despite its central role in P450 function, no direct electrochemical investigation of the purified protein has been reported. Here we report the first voltammetric study of purified human CPR where responses from both the FMN and FAD cofactors have been identified using both cyclic and square wave voltammetry. For human CPR redox responses at −2 and −278 mV (with a ratio of 1e−:3e−) vs NHE were seen at pH 7.9 while the potentials for rat CPR at pH 8.0 were −20 and −254 mV. All redox responses exhibit a pH dependence of approximately −59 mV/pH unit consistent with proton coupled electron transfer reactions of equal stoichiometry. Keywords: Cytochrome P450 reductase, Protein, Voltammetry
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- 2006
17. Direct electrochemistry of enzymes from the cytochrome P450 2C family
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Paul V. Bernhardt, Alka Shukla, Deanne J. Mitchell, and Elizabeth M. J. Gillam
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inorganic chemicals ,chemistry.chemical_classification ,medicine.medical_specialty ,Unspecific monooxygenase ,biology ,Stereochemistry ,Cytochrome P450 ,Metabolism ,Ligand (biochemistry) ,Isozyme ,lcsh:Chemistry ,Electron transfer ,Enzyme ,lcsh:Industrial electrochemistry ,lcsh:QD1-999 ,chemistry ,Biochemistry ,Bioelectrochemistry ,Electrochemistry ,biology.protein ,medicine ,lcsh:TP250-261 - Abstract
The human cytochromes P450 are responsible for the clearance of ∼90% of xenobiotics yet comparatively little is known about their electrochemistry. Here we report the first direct electrochemistry of P450s from the 2C subfamily; one of the major groups of enzymes from this family. Specifically, the proteins that we have examined are recombinant human P450s 2C9, 2C18 and 2C19 and reversible FeIII/II couples are seen in the absence of dioxygen. Even in the presence of trace amounts of dioxygen, a pronounced cathodic response is seen which is assigned to catalytic reduction of the bound dioxygen ligand by the ferrous P450. Keywords: Cytochrome P450, Voltammetry, Direct electron transfer
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- 2005
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18. Adsorption of chromium from aqueous solutions by maple sawdust
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Alka Shukla, Li Jia Yu, John L. Margrave, Shyam S. Shukla, and Kenneth L. Dorris
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Chromium ,Langmuir ,Environmental Engineering ,Sorbent ,Health, Toxicology and Mutagenesis ,Metal ions in aqueous solution ,Inorganic chemistry ,chemistry.chemical_element ,Acer ,engineering.material ,Waste Disposal, Fluid ,Water Purification ,Adsorption ,Environmental Chemistry ,Freundlich equation ,Waste Management and Disposal ,Chelating Agents ,Maple ,Chemistry ,technology, industry, and agriculture ,Wood ,Pollution ,Carcinogens, Environmental ,Ion Exchange ,visual_art ,engineering ,visual_art.visual_art_medium ,Sawdust - Abstract
This paper presents the data for the effect of adsorbent dose, initial sorbate concentration, contact time, and pH on the adsorption of chromium(VI) on maple sawdust. Batch adsorption studies have been carried out. An empirical relationship has been obtained to predict the percentage chromium(VI) removal at any time for known values of sorbent and initial sorbate concentration. Under observed test conditions, the equilibrium adsorption data fits the linear Langmuir and Freundlich isotherms. The experimental result inferred that chelation ion exchange is one of the major adsorption mechanisms for binding metal ions to the maple sawdust.
- Published
- 2003
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19. The removal of heavy metals from aqueous solutions by sawdust adsorption — removal of lead and comparison of its adsorption with copper
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Shyam S. Shukla, Bin Yu, Kenneth L. Dorris, Y Zhang, and Alka Shukla
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Langmuir ,Environmental Engineering ,Sorbent ,Health, Toxicology and Mutagenesis ,Inorganic chemistry ,chemistry.chemical_element ,Waste Disposal, Fluid ,Adsorption ,Desorption ,Industry ,Environmental Chemistry ,Freundlich equation ,Waste Management and Disposal ,Chromatography ,Sorption ,Wood ,Pollution ,Copper ,Kinetics ,Lead ,chemistry ,visual_art ,visual_art.visual_art_medium ,Sawdust - Abstract
In this work, sorption of lead on sawdust (SD) has been studied by using batch techniques. Similar to the sorption of copper, the equilibrium sorption levels for lead is a function of the solution pH, contact time, sorbent and sorbate concentration. The equilibrium adsorption capacity of sawdust for lead was measured and extrapolated using linear Freundlich and Langmuir isotherms and compared with that for copper. Metal ions which are bounded to the sawdust could be stripped by acidic solution so that the sawdust can be recycled. Non-equilibrium experiments were done by using glass columns. The results indicate the potentially practical value of this method in industries and also provide strong evidence to support the adsorption mechanism proposed. Even though the focus of this work is on lead, some results from previous study for copper have been incorporated here for sake of comparison.
- Published
- 2001
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20. The removal of heavy metal from aqueous solutions by sawdust adsorption — removal of copper
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Shyam S. Shukla, Kenneth L. Dorris, Alka Shukla, Bin Yu, and Y Zhang
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Langmuir ,Environmental Engineering ,Chromatography ,Aqueous solution ,Ion exchange ,Chemistry ,Health, Toxicology and Mutagenesis ,Metal ions in aqueous solution ,chemistry.chemical_element ,Dust ,Wood ,Pollution ,Copper ,Water Purification ,Adsorption ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,Environmental Chemistry ,Freundlich equation ,Sawdust ,Waste Management and Disposal ,Water Pollutants, Chemical - Abstract
Locally available sawdust, a byproduct of the world industry, was found to be a low cost and promising adsorbent for the removal of copper(II) from wastewater. In this work, adsorption of copper on sawdust has been studied by using batch techniques. The equilibrium adsorption level was determined to be a function of the solution pH, contact time, and sorbate concentration. The equilibrium adsorption capacity of sawdust for copper was obtained by using linear Freundlich and Langmuir isotherms. Ion exchange is probably one of the major adsorption mechanisms for binding divalent metal ions to the maple sawdust. The results provide strong evidence to support the hypothesis of adsorption mechanism. It also supplies significant sawdust operation capacity data for engineering design.
- Published
- 2000
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21. Association of single nucleotide polymorphisms in vascular endothelial growth factor gene with bladder cancer risk
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Nidhi Tripathi, Praveen Kumar Jaiswal, Rama Devi Mittal, and Alka Shukla
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Male ,Vascular Endothelial Growth Factor A ,Cancer Research ,medicine.medical_specialty ,Angiogenesis ,Single-nucleotide polymorphism ,Biology ,Polymorphism, Single Nucleotide ,Metastasis ,chemistry.chemical_compound ,Risk Factors ,Internal medicine ,Genotype ,Biomarkers, Tumor ,medicine ,Humans ,Genetic Predisposition to Disease ,Genetic Association Studies ,Aged ,Hematology ,Bladder cancer ,Haplotype ,General Medicine ,Middle Aged ,medicine.disease ,Molecular biology ,Vascular endothelial growth factor ,Urinary Bladder Neoplasms ,Oncology ,chemistry ,Case-Control Studies ,Cancer research ,Female - Abstract
Vascular endothelial growth factor (VEGF) is an endothelial cell-specific potent mitogen involved in a number of pathologic processes, including angiogenesis, tumor growth, and metastasis. Polymorphisms of VEGF gene have been associated with susceptibility to several cancers. VEGF gene susceptibility to bladder cancer (BC), however, still remains controversial. We analyzed association of the -2578C/A, -7C/T, -2549I/D, and -1001G/C polymorphism of the VEGF gene with bladder cancer (BC) risk and interaction of these polymorphisms with lifestyle and demographic factors. We genotyped -2578C/A, -7C/T, -2549I/D and -1001G/C by PCR-restriction fragment length polymorphism and amplification refractory mutation specific method to evaluate risk in 200 BC patients and 250 healthy controls from North Indian population. Significant association for BC risk in heterozygous CA genotype (1.69-fold) in VEGF-2578C/A and heterozygous genotype of VEGF-1001G/C (p = 0.032) was observed. Interestingly, VEGF-2549I/D genotype showed reduced risk for BC. The gene-gene combination analysis revealed DD-GG with reduced risk (p = 0.018) of VEGF-2549I/D and VEGF-1001G/C, and combination CA-GG of VEGF-2578C/A and VEGF-1001G/C demonstrated 1.75-fold risk for BC. Our findings suggested that polymorphism -2578C/A and -1001G/C in the promoter of VEGF gene may play a significant role in mediating the bladder cancer risk, whereas VEGF-2549I/D genotype appears to be protective for BC.
- Published
- 2013
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22. Exocytosis, dependent on Ca2+ release from Ca2+ stores, is regulated by Ca2+ microdomains
- Author
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Jiun T. Low, Alka Shukla, Natasha Behrendorff, and Peter Thorn
- Subjects
Cells ,chemistry.chemical_element ,Calcium ,Biology ,Exocytosis ,Cell membrane ,chemistry.chemical_compound ,Mice ,Cytosol ,medicine ,Animals ,Secretion ,Pancrelipase ,Endoplasmic reticulum ,Secretory Vesicles ,Lipid microdomain ,Biological Transport ,Cell Biology ,Secretory Vesicle ,Cell biology ,EGTA ,Kinetics ,medicine.anatomical_structure ,chemistry - Abstract
The relationship between the cellular Ca 2+ signal and secretory vesicle fusion (exocytosis) is a key determinant of the regulation of the kinetics and magnitude of the secretory response. Here, we have investigated secretion in cells where the exocytic response is controlled by Ca 2+ release from intracellular Ca 2+ stores. Using live-cell two-photon microscopy that simultaneously records Ca 2+ signals and exocytic responses, we provide evidence that secretion is controlled by changes in Ca 2+ concentration [Ca 2+ ] in relatively large-volume microdomains. Our evidence includes: (1) long latencies (>2 seconds) between the rise in [Ca 2+ ] and exocytosis, (2) observation of exocytosis all along the lumen and not clustered around Ca 2+ release hot-spots, (3) high affinity ( K d =1.75 μM) Ca 2+ dependence of exocytosis, (4) significant reduction in exocytosis in the prescence of cytosolic EGTA, (5) spatial exclusion of secretory granules from the cell membrane by the endoplasmic reticulum, and (6) inability of local Ca 2+ responses to trigger exocytosis. These results strongly indicate that the control of exocytosis, triggered by Ca 2+ release from stores, is through the regulation of cytosolic [Ca 2+ ] within a microdomain.
- Published
- 2010
23. ChemInform Abstract: High Diastereofacial Selectivity in the Reaction of Silyl Enol Ethers with Chlorosulfides
- Author
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Javed Iqbal and Alka Shukla
- Subjects
Nucleophilic addition ,Silylation ,organic chemicals ,General Medicine ,Enol ,Medicinal chemistry ,Ion ,chemistry.chemical_compound ,nervous system ,chemistry ,health occupations ,Anhydrous ,heterocyclic compounds ,Chelation ,Selectivity ,Zinc bromide - Abstract
The chlorosulfides 1 or 2 react with silyl enol ethers in presence of anhydrous zinc bromide to give mainly the corresponding syn products 4 or 6 respectively. The high syn selectivity of these reaction is explained by nucleophilic addition to a Chelated Chiral thioniun ion.
- Published
- 2010
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24. Solidification/stabilization study for the disposal of pentachlorophenol
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Alka Shukla, Shyam S. Shukla, Tejraj M. Aminabhavi, Kwun-Chi Lee, and Ramachandra H. Balundgi
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Environmental Engineering ,Waste management ,Health, Toxicology and Mutagenesis ,Solidification stabilization ,Pollution ,law.invention ,Pentachlorophenol ,Portland cement ,chemistry.chemical_compound ,chemistry ,law ,Environmental Chemistry ,Leaching (metallurgy) ,Waste Management and Disposal ,Nuclear chemistry - Abstract
Solidification/stabilization of toxic pentachlorophenol (PCP) has been studied by using spectroscopic and electrochemical techniques. Portland type I c
- Published
- 1992
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25. Membrane integration of recombinant human P450 forms
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Weiliang Huang, Alka Shukla, Iris Depaz, and Elizabeth M. J. Gillam
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Health, Toxicology and Mutagenesis ,Toxicology ,Biochemistry ,Substrate Specificity ,Hydroxylation ,chemistry.chemical_compound ,Humans ,Amino Acid Sequence ,Peptide sequence ,Cytochrome P-450 CYP2C9 ,Sequence Deletion ,Pharmacology ,biology ,Endoplasmic reticulum ,Peripheral membrane protein ,Cell Membrane ,Cytochrome P450 ,General Medicine ,Subcellular localization ,Recombinant Proteins ,Cytochrome P-450 CYP2C19 ,Membrane protein ,chemistry ,biology.protein ,Heterologous expression ,Aryl Hydrocarbon Hydroxylases - Abstract
Amino terminal sequence modification of cytochrome P450 enzymes is often necessary to achieve expression in bacteria. The aim of this study was to examine the effect of such modifications on membrane integration and P450 activity. Forms that retained substantial N-terminal hydrophobic sequences remained unaffected by treatments to remove peripheral membrane proteins and were released only by detergent. Truncated P450s 2A13, 2C9 (delta 3-20), 2C19 (delta 3-20), 2D6 (DB11) and 2E1 remained principally membrane-bound, but some P450 was found in the soluble fraction and could be partially extracted by alkaline and high salt treatments. The subcellular localization of P450s 2C9 and 2C19 assessed by fluorescence microscopy mirrored the distribution between subcellular fractions. The MALLLAVFL modified forms of P450 2C9 YFP, P450 2C18 YFP and P450 2C19 YFP were found primarily at the periphery of the cells, whereas the truncated forms of P450 2C9 (delta 3-20) YFP and 2C19 (delta 3-20) YFP were observed at the periphery as well as inside the cells. N-terminal variants of P450s 2C9 and 2C19 showed altered kinetics towards form-selective substrates. Rates of diclofenac 4 -hydroxylation by P450 2C9 and luciferin H-EGE metabolism by P450 2C19 were higher for the MALLLAVFL-modified forms compared with the (delta 3-20) truncated forms despite supplementation of truncated form incubations with additional reductase. Thus, N-terminal sequence modifications changed the degree of membrane integration, potentially affecting subcellular localization, interactions with redox partners, and hence enzymatic activity.
- Published
- 2009
26. High diastereofacial selectivity in the reaction of silyl enol ethers with chlorosulfides
- Author
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Javed Iqbal and Alka Shukla
- Subjects
chemistry.chemical_classification ,Nucleophilic addition ,Silylation ,organic chemicals ,Organic Chemistry ,Biochemistry ,Medicinal chemistry ,Enol ,chemistry.chemical_compound ,Acid catalysis ,SN1 reaction ,nervous system ,chemistry ,Drug Discovery ,health occupations ,Enol ether ,Organic chemistry ,heterocyclic compounds ,Selectivity ,Zinc bromide - Abstract
The chlorosulfides 1 or 2 react with silyl enol ethers in presence of anhydrous zinc bromide to give mainly the corresponding syn products 4 or 6 respectively. The high syn selectivity of these reaction is explained by nucleophilic addition to a Chelated Chiral thioniun ion.
- Published
- 1991
- Full Text
- View/download PDF
27. Cobalt mediated regioselective ring opening of oxiranes with benzenethiol: a mechanistic study
- Author
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Alka Shukla, Rajiv Ranjan Srivastava, Sanjay Tripathi, Anu Pandey, and Javed lqbal
- Subjects
Reaction mechanism ,Organic Chemistry ,chemistry.chemical_element ,Epoxide ,Regioselectivity ,Photochemistry ,Biochemistry ,Medicinal chemistry ,Chloride ,Catalysis ,chemistry.chemical_compound ,Electron transfer ,chemistry ,Drug Discovery ,medicine ,Cobalt ,Bond cleavage ,medicine.drug - Abstract
Oxiranes are regioselectively cleaved by benzenethiol in presence of cobalt(II) chloride or Co2(CO)8 to the corresponding β-hydroxy sulfides in good yields. A mechanistic study of this reaction reveals that an electron transfer process is involved in these transformations and the reaction is proceeding via the formation of a carbon-cobalt bond.
- Published
- 1990
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28. Rapid detection of sewage sample polioviruses by integrated cell culture polymerase chain reaction
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Tapan N. Dhole, Tapas Datta, Rashmi Chowdhary, and Alka Shukla
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Time Factors ,Health, Toxicology and Mutagenesis ,Sample (material) ,Cell Culture Techniques ,Sewage ,India ,Biology ,Toxicology ,medicine.disease_cause ,Rapid detection ,Polymerase Chain Reaction ,Sensitivity and Specificity ,law.invention ,law ,Poliomyelitis eradication ,medicine ,Environmental Microbiology ,Humans ,Polymerase chain reaction ,General Environmental Science ,business.industry ,Poliovirus ,Public Health, Environmental and Occupational Health ,Virology ,Cell culture ,Biological Assay ,Sample collection ,business ,Water Microbiology ,Poliomyelitis - Abstract
The authors' objective in this study was to introduce and evaluate integrated cell culture polymerase chain reaction (ICC-PCR) as a technique for the rapid screening of poliovirus in sewage samples. Researchers are in the last stage of poliomyelitis eradication; however, in a densely populated country such as India, time is the prime factor in the identification of poliovirus circulation and transmission because this virus follows the fecal-oral route for transmission and is excreted in nature. The authors used ICC-PCR to detect poliovirus in sewage samples, and they compared this nonconventional method with conventional cell culture methods to determine sensitivity, accuracy, and the time from sample collection to final results. The ICC-PCR method provided results within 4-5 days of sewage-sample collection; in contrast, the conventional method takes more than 18 days to provide such results. The ICC-PCR method proved to be sensitive, reproducible, and accurate, as well as rapid in its screening of sewage samples for poliovirus. This diagnostic tool may indeed prove quite useful in polio eradication.
- Published
- 2007
29. Removal of nickel from aqueous solutions by sawdust
- Author
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Alka Shukla, Shyam S. Shukla, Li Jia Yu, and Kenneth L. Dorris
- Subjects
Environmental Engineering ,Sorbent ,Health, Toxicology and Mutagenesis ,Metal ions in aqueous solution ,Inorganic chemistry ,chemistry.chemical_element ,Acer ,Adsorption ,Nickel ,Water Pollution, Chemical ,Environmental Chemistry ,Waste Management and Disposal ,Aqueous solution ,Ion exchange ,Chemistry ,Temperature ,Sorption ,Dust ,Hydrogen-Ion Concentration ,Pollution ,Wood ,Solutions ,Kinetics ,Models, Chemical ,visual_art ,visual_art.visual_art_medium ,Sawdust ,Water Pollutants, Chemical - Abstract
The main parameters influencing Nickel (II) metal sorption on maple sawdust were: initial metal ion concentration, amount of adsorbent, and pH value of solution. The maximum percent metal removal was attained after about 1 h. The greatest increase in the rate of adsorption of metal ions on sawdust was observed for pH changes from 2 to 5. An empirical relationship has been obtained to predict the percentage Nickel (II) removal at any time for known values of sorbent and initial sorbate concentration. The experimental results provided evidence for chelation ion exchange as the major adsorption mechanisms for binding metal ions to the sawdust. The adsorbent can be effectively regenerated using 0.1 M strong acid and reused.
- Published
- 2004
30. Exocytosis, Dependent on Calcium Release from Calcium Stores, is Regulated by Calcium Microdomains
- Author
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Alka Shukla, Peter Thorn, and Jiun T. Low
- Subjects
Biophysics ,chemistry.chemical_element ,Biology ,Calcium ,Exocytosis ,Cell biology ,EGTA ,chemistry.chemical_compound ,Cytosol ,chemistry ,Spatial clustering ,Secretion ,biological phenomena, cell phenomena, and immunity ,Intracellular ,Exocytic vesicle - Abstract
The relationship between the cellular Ca2+ signal and exocytic vesicle fusion is a key determinant of the regulation of the kinetics and magnitude of the secretory response. Here, we have investigated secretion in epithelial cells where the exocytic response is controlled by Ca2+ release from intracellular Ca2+ stores (Ueda & Petersen 1977). Using live-cell 2-photon microscopy, identifying each individual exocytic fusion event (Thorn et al., 2004) and recording cytosolic Ca2+ signals with Fura-2 (Nemoto et al., 2001), we show no evidence for spatial clustering of exocytosis; indeed exocytosis is actually specifically excluded from sites of Ca2+ release hot-spots. Consistent with this data, loading the cells with EGTA potently blocks exocytosis. These results indicate that the control of exocytosis, triggered by Ca2+ release from stores, is through the regulation of cytosolic Ca2+ concentrations within large volume microdomains.Nemoto, T., Kimura, R., Ito, K., Tachikawa, A., Miyashita, Y., Iino, M. & Kasai, H. (2001) Nature Cell Biol.3: 253-258.Thorn, P., Fogarty, K.E. & Parker, I. (2004) Proceedings National Academy Science 101:6774-6779Ueda N. & Petersen OH (1997) Pflugers Archiv370: 179-183
- Published
- 2010
- Full Text
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31. Reactions in Micelles, Monolayers, and Liquid Crystals
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E. Lissi, Jason Dennis, Dinesh O. Shah, Daniel I. C. Wang, Shyam S. Shukla, E. O’Sullivan, R. L. Williamson, N. Kallay, M. E. Peña, C. J. Johny, A. J. I. Ward, Shraboni Sarcar, Alka Shukla, S. G. Allenmark, M. J. Minch, J. R. Leis, C. Bravo, H. Voss, Elvira Rodenas, R. A. Thompson, Manisha Pathak, J. P. Wilcoxon, E. Abuin, H. Mohindra Chawla, A. Bommarlusp, Ajay Kumar, T. D. M. Stultz, G. B. Behera, S. S. Katiyar, Y. Yang, C. P. Singh, G. V. Bakore, R. Shanker, P. Miothe, X. Xiang, A. M. Grancaric, A. S. Bommarius, T. A. Hatton, V. C. Reinsborough, Laurence S. Romsted, Neeta Raj Sharma, P. Hervés, Tanoj Kumar Jain, Amarnath Maitra, and E. Perez-Benito
- Subjects
chemistry.chemical_classification ,Aqueous solution ,Ion exchange ,chemistry ,Critical micelle concentration ,Inorganic chemistry ,Cationic polymerization ,Halide ,Salt (chemistry) ,Microemulsion ,Micelle - Abstract
Measurement of product ratios from dediazoniation reactions in acidic aqueous solutions of cationic micelles provides a new method for determining the relative interfacial quantities of weak nucleophiles at the surface of association colloids. We determined product yields by HPLC from decomposition of hydrophobic derivatives of benzenediazonium salts in aqueous solutions of cetyltrimethyl-ammonium halide, CTAX (X =C1− and Br−) micelles and 0.1 M HX with added NaX at 40°C. Estimates of the ion exchange constant, Kcl Br≃3, obtained from product ratios in the presence of mixtures of the two ions are independent of added salt, but decrease to about 2 at high Br- mole ratio. Preliminary results in CTABr micelles show that the method can be used with microemulsions and that added BuOH reduces the quantity of interfacial Br− as expected, but surprisingly not interfacial water. Generous financial support was provided by NIH, NSF-U.S. Brazil Cooperative Program, PRF, Research Corporation and The Research Council and BRSG Fund of Rutgers University.
- Published
- 1991
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- View/download PDF
32. Biodegradation of Nitroaromatic Compounds Edited by Jim C. Spain (Armstrong Laboratory, Tyndall Air Force Base, FL). Plenum Press: New York. 1995. xiii + 232 pp. $79.50. ISBN 0-306-45014-3
- Author
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Alka Shukla
- Subjects
Colloid and Surface Chemistry ,Polymer science ,Chemistry ,General Chemistry ,Biodegradation ,Base (exponentiation) ,Biochemistry ,Plenum space ,Catalysis ,Tyndall - Published
- 1996
- Full Text
- View/download PDF
33. Formulation of mathematical expressions to avoid inaccuracies in computation
- Author
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Alka Shukla and Shyam S. Shukla
- Subjects
Computer based learning ,Computer science ,Computation ,General Chemistry ,Algorithm ,Education - Abstract
67. Bits and pieces, 27. It is important to realize the subtly of the computation and to note that computers have some limitations.
- Published
- 1986
- Full Text
- View/download PDF
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