Combating errors in quantum communication: an integrated approach.

Near-term quantum communication protocols suffer inevitably from channel noises, whose alleviation has been mostly attempted with resources such as multiparty entanglement or sophisticated experimental techniques. Generation of multiparty higher dimensional entanglement is not easy. This calls for exploring realistic solutions which are implementable with current devices. Motivated particularly by the difficulty in generation of multiparty entangled states, in this paper, we have investigated error-free information transfer with minimal requirements. For this, we have proposed a new information encoding scheme for communication purposes. The encoding scheme is based on the fact that most noisy channels leave some quantities invariant. Armed with this fact, we encode information in these invariants. These invariants are functions of expectation values of operators. This information passes through the noisy channel unchanged. Pertinently, this approach is not in conflict with other existing error correction schemes. In fact, we have shown how standard quantum error-correcting codes emerge if suitable restrictions are imposed on the choices of logical basis states. As applications, for illustration, we propose a quantum key distribution protocol and an error-immune information transfer protocol.

Endophyte fungi, Cladosporium species-mediated synthesis of silver nanoparticles possessing in vitro antioxidant, anti-diabetic and anti-Alzheimer activity.

This research study is to develop an easy and eco-friendly method for the synthesis of AgNPs using aqueous extract of endophytic fungi, Cladosporium species (CsAgNPs) and investigated the effects of antioxidant, anti-diabetic and anti-acetylcholinesterase (AChE), anti-butyrylcholinesterase (BChE) activity. Cladosporium species-mediated silver nanoparticles were characterized by UV-Vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The aqueous extract of Cladosporium species has shown the presence of carbohydrates, tannin, phenolic glycosides, terpenoids, alkaloids, phenol and anthraquinones. At 438 nm conformed the absorbance of AgNPs. The SEM result confirms that size, morphology and high density of the synthesized nanoparticles with huge disparity in the particle size distribution. The FTIR analysis confirmed the important biological compounds responsible for reduction of silver. Strong absorption property of AgNPs was studied by EDX. In antioxidant activity, CsAgNPs showed the involvement of NADPH-dependent reductase in the formation of AgNPs. The AgNPs has reduced the activity of α-amylase, α-glucosidase and dipeptidyl peptidase IV in vitro antidiabetic activity. The CsAgNPs showed significant glucose uptake in 3T3L1 cell line. The AgNPs have shown excellent inhibitory activity against AChE and BChE. To our best knowledge, this is the first on the synthesis of silver nanoparticles using endophytic fungi, Cladosporium species isolated from healthy leaf of Loranthus micranthus. Hence, to validate our results the in vivo animal studies at molecular level are needed to develop an antioxidant, anti-diabetic and anti-cholinesterase agent.

Extracellular Synthesis of Selenium Nanoparticles from an Actinomycetes Streptomyces griseoruber and Evaluation of its Cytotoxicity on HT-29 Cell Line.

BACKGROUND: Selenium nanoparticles (SeNPs) have gained significant importance because of its bioavailability, least toxicity, its interaction with proteins and its biocompatibility. OBJECTIVE: In the present study, the extracellular synthesis of SeNPs was carried out by using culture supernatant of Streptomyces griseoruber, an Actinomycetes member isolated from the soil and cytotoxicity was tested on HT-29 cell line. METHODS: Culture supernatant was mixed with 1mM sodium selenite for the biosynthesis of SeNPs. Characterisation of the synthesised SeNPs was done by UV-Visible spectrophotometer, FTIR, XRD, DLS and HR-TEM. The cytotoxicity of nanoparticles on HT-29 cell line was studied by MTT assay and with different staining procedure. RESULTS: Bioreduction of SeNPs was confirmed by UV-Visible spectrophotometer that showed the peak at 575 nm. Size and distribution of the biosynthesised SeNPs were analysed by HR-TEM that showed the formation of particle size in the range of 100-250nm. The synthesised SeNPs showed good cytotoxic activity against HT-29 cell line with 40.5%, 33% and 23.7% of cell viability at 2µg/ ml, 4µg/ml and 30µg/ml concentration respectively. CONCLUSION: The present study reports the simple and eco-friendly synthesis of SeNPs that showed good cytotoxic activity against HT-29 cell line suggesting that biogenic SeNPs could be a potential chemotherapeutic agent.

Acute renal failure in the ICU setting: A prospective observational study.

BACKGROUND: Acute renal failure (ARF) is a common entity in the intensive care unit (ICU) setting. There is scanty data regarding acute kidney injury (AKI) in ICUs from our country and no data from the service setting. METHODS: All patients admitted to the ICU of a tertiary care teaching hospital for six months were included in the study. They were divided into two groups: surg gr (admitted in surgical ICU) and med gr (admitted in medical ICU). During the stay in ICU, patients were observed for the development of AKI depending on the creatinine values and hourly urine output. Staging was done based upon the Risk Injury Failure Loss and End stage kidney (RIFLE) criteria. Relevant data associated with development of AKI was collected for correlation. RESULTS: 17.15% patients developed AKI after admission to the ICU 40% patients admitted with sepsis developed AKI. An increased susceptibility to develop AKI was found on day 4 of admission in both the groups. Of the patients who developed AKI, the surg gr of patients had a higher sequential organ failure assessment (SOFA) score both on day of admission (7.85 vs 5.65) and on the day of development of AKI (9.47 vs 6.18) as compared to the medical group. CONCLUSION: The incidence of ARF in our study was 17.2% with the patients of polytrauma/MODS being of major concern. The initial 3-4 days are the most critical and susceptible patients must be intensive monitored during this time for prevention of ARF. Medical ICU patients develop ARF at a low SOFA score in comparison to surgical ICU patients and thus need greater attention.

Control of hospital acquired infections in the ICU: A service perspective.

BACKGROUND: The service setting has some unique strengths and weaknesses that must be kept in mind when organizing Hospital acquired infections (HAI) prevention interventions. METHODS: Following an initial study to gather data regarding HAI in the Surgical intensive care unit (ICU) we put into place various infection control interventions. The present study was carried out to analyse the effect of these interventions on the incidence of HAI in the ICU. RESULTS: The total admissions to the ICU were 253 patients. Eighty eight patients (34.78%) were admitted for more than 48 hr, 165 patients stayed for less than 48 h. The frequency of HAI was 7.95% (95% CI 3.54, 15). Hospital acquired pneumonia was observed in 2 of the 88 patients (2.27%) (95% CI 0.38, 7.30) which amounted to 9.70 infections per 1000 ventilator days. Bloodstream infection was detected in 3 out of 88 patients (3.4%) (95% CI 0.87, 8.99) amounting to 6.54 fresh infections per 1000 Central Venous Catheter days. Urinary tract infection was observed in 2 (2.27%) (95% CI 0.38, 7.30) at 2.86 fresh infections per 1000 catheter days. As compared to the previous study we found that there was a decline of HAI ranging from 60 to 70%. CONCLUSION: Our study demonstrated that by meticulously following infection control protocols especially tailored to the service setting the incidence of HAI's can be reduced. However, the challenge is in maintaining the gains achieved since there is a rapid turnover of manpower in the ICU and a lack of a structured ICU design model.

Transient leukemia in down syndrome: report of two cases with review of literature.

Transient leukemia (TL) also referred to as transient abnormal myelopoiesis (TAM) or transient myeloproliferative disorder (TMD) is a unique syndrome that frequently occurs in newborns with Down syndrome (DS). It manifests in the first few days of life and shows leukocytosis with blast cells in the blood and bone marrow. This leukemia resolves spontaneously within first few months of life in the majority of cases. In this report we describe two newborns with a karyotype of 47,XY,+21, presented with marked leukocytosis and many blast cells in the peripheral blood. In both the cases, the blasts disappeared and the total leukocyte count reverted to normal without any specific treatment.

Mycotoxins in Food and Feed: Present Status and Future Concerns.

Disease outbreaks due to the consumption of contaminated food and feedstuff are a recurring problem worldwide. The major factor contributing to contamination are microorganisms, especially fungi, which produce low-molecular-weight compounds as secondary metabolites, with confirmed toxic properties referred to as mycotoxins. Several mycotoxins reported to date are cosmopolitan in distribution and incur severe health-associated risks (including cancer and neurological disorders). Hence, creating awareness among consumers, as well as developing new methods for detection and inactivation is of great importance for food safety. In this review, the focus is on the occurrence of various types of mycotoxins in food and feed associated with risks to humans and livestock, as well as legislation put forth by various authorities, and on presently practiced detoxification methods. Brief descriptions on recent developments in mycotoxin detection methodology are also inlcuded. This review is meant to be informative not only for health-conscious consumers but also for experts in the field to pave the way for future research to fill the existing gaps in our knowledge with regard to mycotoxins and food safety.

Exercise-related spontaneous coronary artery dissection: case report and literature review.

BACKGROUND: Spontaneous coronary artery dissection is a rare cause of acute cardiac events and occurs most frequently in the peripartum period. Coronary artery dissection related to exercise is even more unusual, with only a few cases reported in the literature. We report a case of acute coronary artery dissection related to exercise in a 17-yr-old high school athlete, and we review the available literature on exercise-related coronary dissection. METHODS: We performed a PubMed literature search using the search terms exercise, sports, spontaneous coronary dissection, and athletics. We found seven cases of spontaneous coronary artery dissection that had occurred during intense physical exercise. Vigorous exercise can provoke acute ischemic events, but such events occur primarily in adults with atherosclerotic disease. Many of the cases reported as spontaneous coronary artery dissection are more likely atherosclerotic plaque rupture, in which cases they are not truly spontaneous. Because spontaneous coronary dissection is so rare, there are no available recommendations on how to manage young athletes with this condition. We permitted this athlete to return to limited competition, without data to support either a total restriction or even a limited restriction, with the written understanding that a recurrent event is possible but probably unlikely. In summary, spontaneous coronary artery dissection should be considered in young individuals presenting with exercise-related acute ischemic cardiac events.

Enhanced lycopene productivity by manipulation of carbon flow to isopentenyl diphosphate in Escherichia coli.

Lycopene is a useful phytochemical that holds great commercial value. In our study the lycopene production pathway in E. coli originating from the precursor isopentenyl diphosphate (IPP) of the non-mevalonate pathway was reconstructed. This engineered strain of E. coli accumulated lycopene intracellularly under aerobic conditions. As a next step, the production of lycopene was enhanced through metabolic engineering methodologies. Various competing pathways at the pyruvate and acetyl-CoA nodes were inactivated to divert more carbon flux to IPP and subsequently to lycopene. It was found that the ackA-pta, nuo mutant produced a higher amount of lycopene compared to the parent strain. To further enhance lycopene production, a novel mevalonate pathway, in addition to the already existing non-mevalonate pathway, was engineered. This pathway utilizes acetyl-CoA as precursor, condensing it to form acetoacetyl-CoA and subsequently leading to formation of IPP. Upon the introduction of this new pathway, lycopene production increased by over 2-fold compared to the ackA-pta, nuo mutant strain.

Redistribution of metabolic fluxes in the central aerobic metabolic pathway of E. coli mutant strains with deletion of the ackA-pta and poxB pathways for the synthesis of isoamyl acetate.

Although the bacterium E. coli is chosen as the host in many bioprocesses, products derived from the central aerobic metabolic pathway often compete with the acetate-producing pathways poxB and ackA-pta for glucose as the substrate. As such, a significant portion of the glucose may be excreted as acetate, wasting substrate that could have otherwise been used for the desired product. The production of the ester isoamyl acetate from acetyl-CoA by ATF2, a yeast alcohol acetyl transferase, was used as a model system to demonstrate the beneficial effects of reducing acetate production. All strains tested for ester production also overexpressed panK, a native E. coli gene that previous studies have shown to increase free intracellular CoA levels when fed with pantothenic acid. A recombinant E. coli strain with a deletion in ackA-pta produces less acetate and more isoamyl acetate than the wild-type E. coli strain. When both acetate-producing pathways were deleted, the acetate production was greatly reduced. However, pyruvate began to accumulate, so that the overall ester production remained largely unchanged. To produce more ester, a previously established strategy of increasing the flux from pyruvate to acetyl-CoA was adopted by overexpressing pyruvate dehydrogenase. The ester production was then 80% higher in the poxB, ackA-pta strain (0.18 mM) than that found in the single ackA-pta mutant (0.10 mM), which also overexpressed PDH.

Applicability of CoA/acetyl-CoA manipulation system to enhance isoamyl acetate production in Escherichia coli.

Coenzyme A (CoA) and its thioester derivatives are important precursor molecules for many industrially useful compounds such as esters, PHBs, lycopene and polyketides. Previously, in our lab we could increase the intracellular levels of CoA and acetyl-Coenzyme A (acetyl-CoA) by overexpressing one of the upstream rate-controlling enzymes pantothenate kinase with a concomitant supplementation of the precursor pantothenic acid to the cell culture medium. In this study, we showed that the CoA/acetyl-CoA manipulation system could be used to increase the productivity of industrially useful compounds derived from acetyl-CoA. We chose the production of isoamyl acetate as a model system. Isoamyl acetate is an important flavor component of sake yeast and holds a great commercial value. Alcohol acetyl transferase (AAT) condenses isoamyl alcohol and acetyl-CoA to produce isoamyl acetate. The gene ATF2, coding for this AAT was cloned and expressed in Escherichia coli. This genetic engineered E. coli produces isoamyl acetate, an ester, from intracellular acetyl-CoA when isoamyl alcohol is added externally to the cell culture medium. In the current study, we showed that in a strain bearing ATF2 gene, an increase in intracellular CoA/acetyl-CoA by overexpressing panK leads to an increase in isoamyl acetate production. Additionally, the cofactor manipulation technique was combined with more traditional approach of competing pathway deletions to further increase isoamyl acetate production. The acetate production pathway competes with isoamyl acetate production for the common intracellular metabolite acetyl-CoA. Earlier we have shown that acetate pathway deletion (ackA-pta) increases isoamyl acetate production. The acetate production pathway was inactivated under elevated CoA/acetyl-CoA conditions, which lead to a further increase in isoamyl acetate production.

Increasing the acetyl-CoA pool in the presence of overexpressed phosphoenolpyruvate carboxylase or pyruvate carboxylase enhances succinate production in Escherichia coli.

An in vivo strategy to apply the activation effect of acetyl-CoA on phosphoenolpyruvate carboxylase (PEPC) and pyruvate carboxylase (PYC) to increase succinate production in Escherichia coli was studied. This approach relies on the increased intracellular acetyl-CoA and CoA levels by overexpressing E. coli pantothenate kinase (PANK). The results showed that coexpression of PANK and PEPC, and PANK and PYC, did improve succinate production compared to the individual expression of PEPC and PYC, respectively. The intracellular acetyl-CoA and CoA levels were also measured, and each showed a significant increase when the PANK was overexpressed. Another effect observed was a decrease in lactate production. The least amount of lactate was produced when PANK and PEPC, and PANK and PYC, were coexpressed. This result showed increased competitiveness of the succinate pathway at the phosphoenolpyruvate and pyruvate nodes for the carbon flux, as a result reducing the carbon flux toward the lactate pathway. The study also demonstrates a feasible method for metabolic engineering to modulate enzyme activity in vivo through specific activators and inhibitors.

Enhanced isoamyl acetate production upon manipulation of the acetyl-CoA node in Escherichia coli.

Coenzyme A (CoA) and its thioester derivative acetyl-Coenzyme A (acetyl-CoA) participate in over 100 different reactions in intermediary metabolism of microorganisms. Earlier results indicated that overexpression of upstream rate-limiting enzyme pantothenate kinase with simultaneous supplementation of precursor pantothenic acid to the culture media increased intracellular CoA levels significantly ( approximately 10-fold). The acetyl-CoA levels also increased ( approximately 5-fold) but not as much as that of CoA, showing that the carbon flux from the pyruvate node is rate-limiting upon an increase in CoA levels. In this study, pyruvate dehydrogenase was overexpressed under elevated CoA levels to increase carbon flux from pyruvate to acetyl-CoA. This coexpression did not increase intracellular acetyl-CoA levels but increased the accumulation of extracellular acetate. The production of isoamyl acetate, an industrially useful compound derived from acetyl-CoA, was used as a model reporter system to signify the beneficial effects of this metabolic engineering strategy. In addition, a strain was created in which the acetate production pathway was inactivated to relieve competition at the acetyl-CoA node and to efficiently channel the enhanced carbon flux to the ester production pathway. The synergistic effect of cofactor CoA manipulation and pyruvate dehydrogenase overexpression in the acetate pathway deletion mutant led to a 5-fold increase in isoamyl acetate production. Under normal growth conditions the acetate pathway deletion mutant strains accumulate intracellular pyruvate, leading to excretion of pyruvate. However, upon enhancing the carbon flux from pyruvate to acetyl-CoA, the excretion of pyruvate was significantly reduced.

Cofactor engineering of intracellular CoA/acetyl-CoA and its effect on metabolic flux redistribution in Escherichia coli.

Coenzyme A (CoA) and its thioester derivatives are important cofactors participating in over 100 different reactions in intermediary metabolism of microorganisms. The time profiles of intracellular CoA and acetyl-CoA levels were studied in an aerobic batch reactor. The CoA level starts at a high value and falls off gradually over the exponential and stationary growth phases, reaching negligible levels at the end of 24h. The acetyl-CoA level, on the other hand, increases initially reaching a maximum and decreases gradually reaching negligible levels after 24h. Overexpressing one of the upstream rate-controlling enzyme the pantothenate kinase with simultaneous supplementation of the precursor pantothenic acid to the culture medium increased the intracellular CoA/acetyl-CoA levels. It was found that supplementation of the precursor pantothenic acid is essential to increase CoA/acetyl-CoA levels. A 10-fold increase in CoA level was observed upon this overexpression in complex medium. Acetyl-CoA levels also increased (5-fold) but not as much as CoA, leaving much of the CoA in free unacetylated form. The increase in intracellular CoA/acetyl-CoA levels led to an increase in carbon flux to the acetate production pathway leading to formation of more acetate in complex medium, whereas no such change in metabolite redistribution was observed in minimal medium.

Production mechanism of quark-gluon plasma in heavy-ion collisions.

A general scheme is proposed here to describe the production of semihard and soft quarks and gluons that form the bulk of the plasma in ultrarelativistic heavy-ion collisions. We show how to obtain the production rates in the extended phase space, including the color part, as a function of time in a consistent manner and without having to make ad hoc assumptions. All the required features-the back reaction on QCD vacuum, the non-Markovian nature of the production, and the quasi particle nature of the partons-are naturally incorporated. We illustrate the results with a realistic albeit toy model and also show how physically tenable source terms may be obtained.

REVASCULARIZATION OF THE ISCHEMIC UPPER LIMB.

Eighteen cases of upper limb ischemia were operated during a 24 month period. Eleven patients presented with features of chronic ischemia, while 7 had acute ischemia with a threatened limb. There were 15 males and 3 females. The average age was 38 years. Associated medical problems were present in 8 patients. Limb perfusion was restored in all patients after direct arterial (bypass) surgery, intra-arterial thrombolysis or percutaneous transluminal angioplasty (PTA). There was no mortality. The limb salvage rate was 100 per cent. Follow-up of upto 24 months reveals a patent bypass in all patients with no recurrence of symptoms. Upper limb ischemia is not uncommon, and can be treated by thrombolysis, angioplasty or bypass surgery. Direct arterial surgery for upper limb revascularization, though technically demanding, is safe and results in relief of symptoms in the vast majority of patients.