Astaxanthin supplementation ameliorates simulated heat stress by regulating physio-biochemical responses in Sirohi goats.

The present study was undertaken to assess the ameliorative effect of dietary supplementation of astaxanthin in Sirohi goats under simulated heat stress conditions. Eighteen healthy female Sirohi goats were divided equally into three groups (n = 6): Heat-Stressed Control (HSC), Treatment 1 (T1), and Treatment 2 (T2). During the experiment, goats in the T1 group were supplemented with astaxanthin at the rate of 25 mg/animal/day, while those in the T2 group received supplementation of 50 mg/animal/day. The experiment was conducted for 42 days: 14 days of acclimatization period, next 21 days animals were exposed to 42ºC for 6 h from 09:00 h to 15:00 h and 7 days of recovery period. On a daily basis, we recorded the physiological responses of goats and collected environmental data at the experimental site. Blood samples were collected 0 and 14th days of acclimatization, on 1st, 6th, 11th, 16th and 21st day of heat exposure and on the 7th day of the recovery period. The rectal temperature and respiration rates of the treatment groups were lower than those of the HSC group during the exposure period. Heat stress in the supplemented groups was associated with reduced levels of hepatic enzymes such as AST and ALT. Serum urea, creatinine and albumin levels were significantly (P < 0.05) different between control and treatment groups. It was thus concluded that dietary inclusion of antioxidant astaxanthin can ameliorate induced thermal load as evident from changes in physio-biochemical parameters in the Sirohi goats, that was more prominent at 50 mg/ animal/day than 25 mg/ animal/day.

Neonatal Brain Temperature Monitoring Based on Broadband Near-Infrared Spectroscopy.

We present here the initial development of a novel algorithm based on broadband near-infrared spectroscopy (bNIRS) data to estimate the changes in brain temperature (BT) in neonates. We first explored the validity of the methodology on a simple numerical phantom and reported good agreements between the theoretical and retrieved values of BT and hemodynamic parameters changes, which are the parameters usually targeted by bNIRS. However, we noted an underestimation of the absolute values of temperature and haemoglobins' concentration changes when large variations of tissue saturation were induced, probably due to a crosstalk between the species in this specific case. We then tested this methodology on data acquired on 2 piglets during a protocol that induces seizures. We showed that despite a decrease in rectal temperature (RT) over time (-0.1048 °C 1.5 h after seizure induction, 95% CI: -0.1035 to -0.1061 °C), BT was raising (0.3122 °C 1.5 h after seizure induction, 95% CI: 0.3207 to 0.3237 °C). We also noted that the piglet displaying the largest decrease in RT also displays the highest increase in BT, which could be a marker of the severity of the seizure induced brain injury. These initial results are encouraging and show that having access to the changes in BT non-invasively could help to better understand the impact of BT on injury severity and to improve the current cooling methodologies in the neonatal neurocritical care following neonatal encephalopathy.

Anaesthetic management of people with multiple sclerosis.

There is a lack of published guidelines on the management of patients with multiple sclerosis (MS) undergoing procedures that require anaesthesia and respective advice is largely based on retrospective studies or case reports. The aim of this paper is to provide recommendations for anaesthetists and neurologists for the management of patients with MS requiring anaesthesia. This review covers issues related to the anaesthetic management of patients with MS, with a focus on preoperative assessment, choice of anaesthetic techniques and agents, side-effects of drugs used during anaesthesia and their potential impact on the disease evolution, drug interactions that may occur, and the need to use monitoring devices. A systematic PubMed research was performed to retrieve relevant articles.

Evaluation of thermo-adaptability between Tharparkar (Bos indicus) and crossbred (Bos indicus X Bos taurus) calves in a controlled environment.

The global warming driven climate change has increased the susceptibility of livestock around the globe to heat stress (HS), which reduces animal productivity and threatens the sustainability of marginal farmers. The objective of this investigation was to evaluate thermo-adaptability between Tharparkar calves (TC), an indigenous milch breed of India and crossbred calves (CC) during induced heat stress in controlled environment. For this purpose, 12 apparently healthy male calves (six in each group) aged 5-6 months, were selected. The experiment was conducted at physiologically comfortable temperature (25 °C), moderate HS (31 °C) and severe HS (37 °C) for 21 days each in a psychrometric chamber. In each experimental day, the calves were exposed to 6 h of heat. There were 7 days of acclimatization period before experiment and 10 days of recovery period at ambient temperature between each 21 day exposure period. During experimental period, the blood was collected at 1st, 6th, 11th, 16th, 21st day and among ten-day recovery period the blood was collected at 5th day. Physiological responses, serum electrolytes, metabolic enzymes profiles, antioxidant capacity, oxidative stress status and general endocrine milieu were studied. Relative mRNA expression study of Heat Shock Protein (HSP) 70, HSP90, induced Nitric Oxide Synthase (iNOS) and endothelial NOS (eNOS) were carried out by qPCR. There was significant (p < 0.05) change in the displacement in rectal temperature, respiration rate, serum alanine aminotransferase level between two breeds at moderate and severe HS. Similar change was observed in total antioxidant capacity, superoxide dismutase, and endocrinological parameters. The comparatively lower mRNA expression of HSP70 and higher expression of HSP90 in TC than CC point the better thermo-adaptability of the same. The results of the experiment indicated that TC are more thermo-adaptable than CC at different modality of stress in controlled temperature conditions.

Genetic interaction between RLM1 and F-box motif encoding gene SAF1 contributes to stress response in Saccharomyces cerevisiae.

BACKGROUND: Stress response is mediated by the transcription of stress-responsive genes. The F-box motif protein Saf1p is involved in SCF-E3 ligase mediated degradation of the adenine deaminase, Aah1p upon nutrient stress. The four transcription regulators, BUR6, MED6, SPT10, SUA7, are listed for SAF1 in the genome database of Saccharomyces cerevisiae. Here in this study, we carried out an in-silico analysis of gene expression and transcription factor databases to understand the regulation of SAF1 expression during stress for hypothesis and experimental analysis. RESULT: An analysis of the GEO profile database indicated an increase in SAF1 expression when cells were treated with stress agents such as Clioquinol, Pterostilbene, Gentamicin, Hypoxia, Genotoxic, desiccation, and heat. The increase in expression of SAF1 during stress conditions correlated positively with the expression of RLM1, encoding the Rlm1p transcription factor. The expression of AAH1 encoding Aah1p, a Saf1p substrate for ubiquitination, appeared to be negatively correlated with the expression of RLM1 as revealed by an analysis of the Yeastract expression database. Based on analysis of expression profile and regulatory association of SAF1 and RLM1, we hypothesized that inactivation of both the genes together may contribute to stress tolerance. The experimental analysis of cellular growth response of cells lacking both SAF1 and RLM1 to selected stress agents such as cell wall and osmo-stressors, by spot assay indicated stress tolerance phenotype similar to parental strain however sensitivity to genotoxic and microtubule depolymerizing stress agents. CONCLUSIONS: Based on in-silico and experimental data we suggest that SAF1 and RLM1 both interact genetically in differential response to genotoxic and general stressors.

Do bisphosphonates alter the clinico-radiological profile of children with Perthes disease? A systematic review and meta-analysis.

This meta-analysis is aimed to analyze the efficacy of bisphosphonates in the management of Perthes disease. A total of 8 animal and 7 human studies have been shortlisted for this analysis. In human studies, common variables for pain, Harris Hip Score (HHS), propensity for femoral head collapse, and total hip arthroplasty (THA), were assessed. In contrast, in animal studies, the data was recorded for epiphyseal quotient, trabecular volume, trabecular separation, trabecular thickness, and trabecular number. Meta-analysis of human studies on ONFH (Osteo-Necrosis of Femoral Head) revealed a statistically significant outcome in HHS [p<0.001; (95% CI: 4.79 - 8.87)], collapse of the femoral head [p=0.079; (95% CI: -0.16 - 0.01)], and THA [p=0.002; (95% CI: -0.19 - -0.04)] whereas the pain score showed an insignificant outcome [p=0.067; (95% CI: -0.62 - 0.04)]. The meta-analysis of selected variables in animal studies revealed a noteworthy outcome in bone volume (p<0.001, 95% Cl), trabecular number (p<0.001, 95% Cl), trabecular thickness (p<0.013, 95% Cl) and trabecular separation (p<0.026, 95% Cl) but not in epiphyseal quotient. Further, analysis of stratified datasets in animal studies revealed a contradictory outcome with significant observations described later in the paper. The use of bisphosphonates holds a promising treatment option in Perthes disease. Although, good quality RCTs are needed to validate it further.

State Readout of a Trapped Ion Qubit Using a Trap-Integrated Superconducting Photon Detector.

We report high-fidelity state readout of a trapped ion qubit using a trap-integrated photon detector. We determine the hyperfine qubit state of a single ^{9}Be^{+} ion held in a surface-electrode rf ion trap by counting state-dependent ion fluorescence photons with a superconducting nanowire single-photon detector fabricated into the trap structure. The average readout fidelity is 0.9991(1), with a mean readout duration of 46 µs, and is limited by the polarization impurity of the readout laser beam and by off-resonant optical pumping. Because there are no intervening optical elements between the ion and the detector, we can use the ion fluorescence as a self-calibrated photon source to determine the detector quantum efficiency and its dependence on photon incidence angle and polarization.

Single-photon detection in the mid-infrared up to 10 µm wavelength using tungsten silicide superconducting nanowire detectors.

We developed superconducting nanowire single-photon detectors based on tungsten silicide, which show saturated internal detection efficiency up to a wavelength of 10 µm. These detectors are promising for applications in the mid-infrared requiring sub-nanosecond timing, ultra-high gain stability, low dark counts, and high efficiency, such as chemical sensing, LIDAR, dark matter searches, and exoplanet spectroscopy.

A systematic review and meta-analysis of cancer patients affected by a novel coronavirus.

BACKGROUND: Cancer patients with COVID-19 disease have been reported to have double the case fatality rate of the general population. MATERIALS AND METHODS: A systematic search of PubMed/MEDLINE, Embase, Cochrane Central, Google Scholar, and MedRxiv was done for studies on cancer patients with COVID-19. Pooled proportions were calculated for categorical variables. Odds ratio and forest plots were constructed for both primary and secondary outcomes. The random-effects model was used to account for heterogeneity between studies. RESULTS: This systematic review of 31 studies and meta-analysis of 181,323 patients from 26 studies involving 23,736 cancer patients is the largest meta-analysis to the best of our knowledge assessing outcomes in cancer patients affected by COVID-19. Our meta-analysis shows that cancer patients with COVID-19 have a higher likelihood of death (odds ratio, OR 2.54), which was largely driven by mortality among patients in China. Cancer patients were more likely to be intubated, although ICU admission rates were not statistically significant. Among cancer subtypes, the mortality was highest in hematological malignancies (OR 2.43) followed by lung cancer (OR 1.8). There was no association between receipt of a particular type of oncologic therapy and mortality. Our study showed that cancer patients affected by COVID-19 are a decade older than the normal population and have a higher proportion of co-morbidities. There was insufficient data to assess the association of COVID-directed therapy and survival outcomes in cancer patients. Despite the heterogeneity of studies and inconsistencies in reported variables and outcomes, these data could guide clinical practice and oncologic care during this unprecedented global health pandemic. CONCLUSION: Cancer patients with COVID-19 disease are at increased risk of mortality and morbidity. A more nuanced understanding of the interaction between cancer-directed therapies and COVID-19-directed therapies is needed. This will require uniform prospective recording of data, possibly in multi-institutional registry databases.

Remote sensing and GIS based analysis of temporal land use/land cover and water quality changes in Harike wetland ecosystem, Punjab, India.

Wetlands help in maintaining ecological balance in an area, but are shrinking fast all over the world. A study was conducted on the Harike wetland in Punjab state of India to analyze temporal changes in land use/land cover (LULC), water spread area and water pollution by using RS and GIS techniques. The LULC map of Harike wetland ecosystem covering an area of 22213.91 ha was prepared through on-screen visual interpretation of multispectral Resourcesat 2 LISS-IV satellite data (2014 and 2018) having spatial resolution of 5.8 m. Area under agriculture, forest and built up increased and that under waste land, water bodies and wetland decreased during 2014-18. The rate of increase in agricultural land was quite high (18.87 ha/year) during 2006-2014, but reduced to 3.53 ha/year during 2014-2018. The built up land increased comparatively at low rates (0.87 and 0.90 ha/year). Areas under waste land, water bodies and wetland decreased at the rate of 4.32, 1.61 and 13.80 ha/year during 2006-2014 and 2.37, 0.34 and 1.71 ha/year during 2014-2018, respectively. The water spread area of Harike wetland which was 4073 ha and 4166 ha in year 2002 and 2006 reduced to 3918.98 ha and 3910.56 ha in the year 2014 and 2018, respectively. However, wetland ponded area shrinked at a rate of 30.37 ha/year during 2006-2014 and 2.11 ha/year during the period 2014-2018. The area under low and medium turbidity increased by 22.02% and 15.2%, respectively, but decreased by 49% under high turbidity during 2014-18. Wetland water was observed to be rich in macro and micronutrients. The pH, BOD and COD of wetland water increased by 0.51, 9.7 mg/l and 24 mg/l, respectively, during 2002-14 and by 0.03, 2.0 mg/l and 5.92 mg/l, respectively during 2014-18. Interaction between land use, water quality, water inflow, ground water and wetland area has also been studied. Intensive cultivation and declining groundwater levels in the area are negatively affecting the wetland. This necessitates regular monitoring of wetland structural components and water quality along with an urgent plan in place for conservation, rehabilitation and management of Harike wetland ecosystem in participatory mode.

Ethnopharmacology-aided antiplasmodial evaluation of six selected plants used for malaria treatment in Nigeria.

ETHNOPHARMACOLOGICAL RELEVANCE: Sub - Saharan Africa has a high malaria burden and Nigeria accounts for majority of malaria cases worldwide. The aim of this study was to evaluate selected plants extracts used against malaria in Nigeria for antiplasmodial activity. MATERIALS AND METHODS: An ethnomedicinal based - approach by literature survey was used to identify plants used in the study. The parts of the plant used were collected and extracted with 70% v/v ethanol; a portion of each extract was used to prepare successive solvent and residual fractions. Chloroquine-sensitive (3D7) P. falciparum strain and human embryonic kidney cells (HEK293) were used for antiplasmodial and cytotoxicity screening respectively. Hemolysis assay was also carried out on red blood cells (RBCs). Test for in vivo efficacy of an active extract was conducted in a mouse model of established P. berghei ANKA-infection. RESULTS: A total of six plants; Andropogon schirensis, Celtis durandii, Chasmanthera dependens, Daniellia ogea, Icacina trichantha and Triumfetta cordifolia were selected and screened. Triumfetta cordifolia leaf extract was observed to display moderate in vitro antiplasmodial activity (IC50 = 48.09 µg/ml) and was non-toxic to HEK293 cells and erythrocytes. At a dose of 400 mg/kg, T. cordifolia significantly (p<0.001) suppressed parasitemia, significantly (p<0.001) inhibited RBC depletion and prolonged survival in infected mice. CONCLUSIONS: T. cordifolia ethanol extract possesses antiplasmodial efficacy and this is the first report of its kind on the plant. It is a potential candidate for further studies to identify its mechanism of action.

Post-treatment mortality after definitive chemoradiotherapy versus resection for esophageal cancer.

In efforts to better characterize incidence and predictors of 30- and 90-day mortality following operative versus nonoperative approaches for locally advanced esophageal cancer (EC), we conducted a novel investigation of a large, contemporary US database. The National Cancer Database was queried for newly-diagnosed T1-3N0-1 squamous cell or adenocarcinoma receiving surgical-based therapy (esophagectomy alone or preceded by chemotherapy and/or radiotherapy) versus definitive chemoradiotherapy (dCRT). Statistics included graphing cumulative incidences of mortality before and following propensity score matching (PSM), based on age-based intervals. Cox regression determined factors independently predictive of 30- and 90-day mortality. Of 15,585 patients, 9,278 (59.5%) received surgical-based therapy and 6,307 (40.5%) underwent dCRT. In the unadjusted population, despite nonsignificant differences at 30 days (3.3% dCRT, 3.6% surgical-based), the dCRT cohort experienced higher 90-day mortality (11.0% vs. 7.5%, P < 0.001). Following PSM, however, dCRT patients experienced significantly lower 30-day mortality (P < 0.001), with nonsignificant differences at 90 days (P = 0.092). Surgical-based management yielded similar (or better) mortality as dCRT in ≤70-year-old patients; however, dCRT was associated with reduced mortality in subjects > 70 years old. In addition to the intervention group, factors predictive for 30- and 90-day mortality included age, gender, insurance status, facility type, comorbidity index, tumor location, histology, and T/N classification. In summary, surgical-based therapy for EC is associated with higher 30-day mortality, which becomes statistically similar to dCRT by 90 days. Differences between surgery and dCRT were most pronounced in patients > 70 years of age. These data may better inform shared decision-making between multidisciplinary providers and patients.

in silico screening and molecular dynamics simulations study to identify novel potent inhibitors against Mycobacterium tuberculosis DnaG primase.

Tuberculosis remains a major global health threat killing millions of people. Due to existing multiple drug resistance (MDR) and prolonged treatment it becomes necessary to explore novel drug targets in Mycobacterium tuberculosis (Mtb). DnaG primase, having a significant role in primer synthesis during initiation of DNA replication, has emerged as a promising drug target. The three dimensional (3D) model of its catalytic domain (Toprim) was constructed. Further, in silico screening of the three diverse chemical compound libraries against the modeled domain was carried out. Four top screened compounds were identified and evaluated by ADMET analysis. The stability of these compounds in complex with the Toprim domain was validated through 50 ns molecular dynamics simulations. Lys 101, Glu 137 and Asp 188 in the active site predominantly formed the hydrogen bonds with the top screened compounds. Hence, the drug-like compounds identified can be taken up for the further experimental investigation as anti-tubercular agents.

Alpha lipoic acid supplementation ameliorates the wrath of simulated tropical heat and humidity stress in male Murrah buffaloes.

A supplement which ameliorates temperature-humidity menace in food producing livestock is a prerequisite to develop climate smart agricultural packages. A study was conducted to investigate the heat stress ameliorative efficacy of alpha lipoic acid (ALA) in male Murrah water buffaloes (Bubalus bubalis). Eighteen animals (293.61 ± 4.66Kg Bwt) were randomly allocated into three groups (n = 6); NHSC (non-heat-stressed control), HS (heat-stressed) and HSLA (heat-stressed-supplemented with ALA@32 mg/kg Bwt orally) based on the temperature humidity index (THI) and ALA supplementation. HS and HSLA were exposed to simulated heat challenge in a climatically controlled chamber (40 °C) for 21 consecutive days, 6 h daily. Physiological responses viz. Respiration rate (RR), Pulse rate (PR) and Rectal temperature (RT) were recorded daily before and after heat exposure. Blood samples were collected at the end of heat exposure on days 1, 6, 11, 16, and 21 and on day 28 (7th day post exposure which is considered as recovery) for peripheral blood mononuclear cells (PBMCs) separation, followed by RNA and Protein extraction for Real time quantitative PCR and Western blot analysis respectively, of heat shock proteins (HSPs). Two-way repeated measure ANOVA was performed between groups at different experimental periods. RR (post exposure) in HS and HSLA was significantly higher (P < 0.05) than NHSC from day 1 onwards but HSLA varied significantly from the HS 8th day onwards. Post exposure RT and PR in both HS and HSLA varied (P < 0.05) from NHSC throughout the study; but between HS and HSLA, RT significantly varied on initial 2 days and last 6 days (from days 16 to 21). HSP70 mRNA expression significantly up regulated in high THI groups with respect to the low THI group throughout the experimental period. During chronic stress (days 16 and 21) HSP70 significantly (P < 0.05) increased in HS but not in HSLA (P > 0.05) with respect to NHSC. ALA supplementation up-regulates and sustains (P < 0.05) the expression of HSP90 in HSLA in comparison to the HS and NHSC. HSP105 expression was significantly up-regulated (P < 0.05) in HS on days 16 and 21 (during long-term exposure) but only on day 21 (P < 0.05) in HSLA. HSP70, HSP90, and HSP105 protein expression dynamics were akin to the mRNA transcript data between the study groups. In conclusion, supplementing ALA ameliorates the deleterious effect of heat stress as reflected by improved physiological and cellular responses. ALA supplementation improved cellular antioxidant status and sustained otherwise easily decaying heat shock responses which concertedly hasten the baton change from a limited window of thermo tolerance to long run acclimatization.

Neoadjuvant denosumab: its role and results in operable cases of giant cell tumour of bone.

AIMS: The aims of this study were to evaluate the efficacy of preoperative denosumab in achieving prospectively decided intention of therapy in operable giant cell tumour of bone (GCTB) patients, and to document local recurrence-free survival (LRFS). PATIENTS AND METHODS: A total of 44 patients received preoperative denosumab: 22 to facilitate curettage, 16 to facilitate resection, and six with intent of converting resection to curettage. There were 26 male and 18 female patients. The mean age was 27 years (13 to 47). RESULTS: The mean number of denosumab treatments was five (2 to 7) per patient. In 42 of 44 patients (95%), denosumab helped to achieve prospectively decided intention. A total of 41 patients were available for follow-up at a mean follow-up of 34 months (24 to 48). There were 12 local recurrences (29%), in 11 patients (11/25, 44%) who had curettage and in one patient (1/16, 6%) who had resection. The mean time to local recurrence was 16 months (8 to 25). The LRFS was 76% at two years: 94% for cases with resection and 64% for cases with curettage (p = 0.013). CONCLUSION: Although local control rates are unlikely to improve with use of preoperative denosumab, a short preoperative course of denosumab can facilitate surgery in certain cases of operable GCTB, with a high risk of local recurrence making curettage or resection technically easier. It may also help in converting a lesion requiring resection to a lesion that could possibly be treated with curettage.

A superconducting thermal switch with ultrahigh impedance for interfacing superconductors to semiconductors.

A number of current approaches to quantum and neuromorphic computing use superconductors as the basis of their platform or as a measurement component, and will need to operate at cryogenic temperatures. Semiconductor systems are typically proposed as a top-level control in these architectures, with low-temperature passive components and intermediary superconducting electronics acting as the direct interface to the lowest-temperature stages. The architectures, therefore, require a low-power superconductor-semiconductor interface, which is not currently available. Here we report a superconducting switch that is capable of translating low-voltage superconducting inputs directly into semiconductor-compatible (above 1,000 mV) outputs at kelvin-scale temperatures (1K or 4 K). To illustrate the capabilities in interfacing superconductors and semiconductors, we use it to drive a light-emitting diode (LED) in a photonic integrated circuit, generating photons at 1K from a low-voltage input and detecting them with an on-chip superconducting single-photon detector. We also characterize our device's timing response (less than 300 ps turn-on, 15 ns turn-off), output impedance (greater than 1MΩ), and energy requirements (0.18fJ/µm2,3.24mV/nW).

Trimodality therapy for esophageal cancer at high volume facilities is associated with improved postoperative outcomes and overall survival.

Trimodality therapy is the standard of care for locally advanced resectable esophageal cancer (EC) but carries morbidity and mortality risks; thus, therapy at high-volume facilities (HVFs) may offer advantages. This investigation studied postoperative outcomes and overall survival (OS) in EC patients receiving trimodality therapy at HVFs versus lower-volume facilities (LVFs). The National Cancer Data Base was queried for patients with locally advanced EC receiving trimodality therapy. HVFs referred to the 90th percentile of case volume. Multivariate logistic regression determined factors associated with treatment at HVFs, the Kaplan-Meier analysis compared OS between the HVF and LVF groups, and the Cox proportional hazards modeling determined variables associated with OS. Sensitivity analysis evaluated the impact of varying the HVF definition cutoff on OS. A total of 3,229 patients met study criteria, including 330 (10%) treated at HVFs and 2,899 (90%) at LVFs. Treatment at HVFs was associated with decreased 30-day mortality (1.2% vs. 3.3%, P = 0.044) and trends toward lower 90-day mortality (4.8% vs. 7.8%, P = 0.055) and the length of postoperative hospitalization (11.2 vs. 12.3d, P = 0.059). HVF patients experienced higher median OS (55 vs. 36 months, P = 0.004), which also independently correlated on the Cox multivariate analysis (P = 0.001). Sensitivity analysis showed similar results as the HVF/LVF cutoff was decreased until the 80th percentile. This is the first study demonstrating that the trimodality management of EC at HVFs is associated with improved postoperative outcomes and survival. These data have implications for multidisciplinary oncologic providers, in addition to patient counseling by both referring and treating clinicians.

Stem cell niche: Dynamic neighbor of stem cells.

Stem cell niche is a specialized and dynamic microenvironment around the stem cells which plays a critical role in maintaining the stemness properties of stem cells. Over the years, advancement in the research activity has revealed the various important aspects of stem cell niche including cell-cell interaction, cell-extracellular matrix interaction, a large number of soluble signaling factors and various biochemical and biophysical cues (such as oxygen tension, flow, and shear and pore size). Stem cells have the potential to be a powerful tool in regenerative medicine due to their self-renewal property and immense differentiation potential. Recent progresses in in vitro culture conditions of embryonic stem cells, adult stem cells and induced pluripotent stem cells have enabled the researchers to investigate and understand the role of the microenvironment in stem cell properties. The engineered artificial stem cell niche has led to a better execution of stem cells in regenerative medicine. Here we elucidate the key components of stem cell niche and their role in niche engineering and stem cell therapeutics.