Abstract: Sentiment analysis is one of the major tasks of NLP. In this paper, we analyzed sentiment of covid-19 tweets using popular data science tools and divided this data into three categories- positive, negative, and neutral. we prepared this model to predict the category of the tweet using different supervised classifiers and examined their accuracy. Keywords: NLP, Covid-19, Sentiment Analysis, TextBlob, KNN (K-Nearest Neighbor), RF (Random Forest), NB (Naïve Bayes) classifiers

The purpose of this paper is to empirically test a conceptual framework based upon three constructs, i.e.: 1) top level management (TLM); 2) clear vision (CV); 3) support from government (SFG). TLM is measured in terms of: 1) qualification of employees; 2) behaviour with subordinates; 3) strategic planning; 4) long-term goals. CV is measured in terms of: 1) willingness of employees to change; 2) long-term planning; 3) core competency; 4) scheduling. Availability of SFG is measured in terms of: 1) infrastructure facility; 2) availability of loans; 3) adequate supply of energy; 4) feasibility of trading; 5) approval of project; 6) government's cooperation. Various statistical techniques were used to verify, validate and test the reliability of the hypothesis and their sub-dimensions. Results of structural equation modelling (SEM) revealed that TLM dimension has a direct and significant impact towards CV (0.83) and SFG (0.62). Also, CV dimension shows a direct, positive impact on SFG (0.70).

Conventional BCS superconductors are expected to exhibit a conductivity with vanishing dissipation with decreasing temperature. While bulk physical properties measurements indicate PdPb$_{2}$ is a conventional superconductor with a $T_c$ of 3.0 K, measurements of surface impedance through the microwave cavity perturbation technique indicate a large, non-vanishing dissipative component below $T_c$ that is at odds with conventional superconductivity. We demonstrate PdPb$_2$ to be a possible topological superconductor with a fully gapped bulk and a dissipative Majorana fluid surface.

Piperine a trans–trans isomer of 1-piperoyl-piperidine was evaluated for its immunomodulatory activity to enhance the efficacy of rifampicin in a murine model of Mycobacterium tuberculosis infection. In-vitro immunomodulation of piperine was tested on mouse splenocytes for lymphocyte proliferation, cytokine production and macrophage activation. Protective efficacy of piperine was tested in a mice infection model of M. tuberculosis for the activation of Th-1 response and synergistic combination efficacy with rifampicin. Murine splenocytes exposed to piperine exhibited proliferation of T and B cell, increased Th-1 cytokines and enhanced macrophage activation. Piperine (1 mg/kg) in mice infected with M. tuberculosis activated the differentiation of T cells into Th-1 sub-population (CD4+/CD8+ subsets). There was an increase in secretion of Th-1 cytokines (IFN-γ and IL-2) by these cells. The qRT-PCR studies revealed corresponding increases in the mRNA transcripts of IFN-γ and IL-2 in the infected lung tissues. Combination of piperine and rifampicin (1 mg/kg) exhibited better efficacy of and resulted in additional 1.4 to 0.8 log reduction in lung cfu as compared to rifampicin alone. The up-regulation of Th1 immunity by piperine can be synergistically combined with rifampicin to improve its therapeutic efficacy in immune-compromised TB patients.

Argyrolobium roseum (Papilionaceae) is a sexually reproducing, rare, annual herb that grows in tropical and sub-temperate tracts of the north-western Himalayan region of the Indian subcontinent. The present investigation was carried out to study the immunomodulatory properties of this herb in well established experimental models. For preliminary pharmacological activity evaluation, we first studied the effect of aqueous fraction (KA-134) of A. roseum on humoral and cell mediated immune responses and found that KA-134 dose dependently suppressed the antibody titre and delayed type hypersensitivity reaction. Inspired by the results, we further fractionated KA-134 which yielded pinitol, which on further immunomodulatory studies resulted in highly significant inhibition of CD3, CD19, CD4 and CD8 count and Th1/Th2 cytokines expression in splenocytes. Pinitol was also found to be safe when tested against cell viability assays (in vitro and in vivo). Based on the data, it can be suggested that pinitol is a potent and non-toxic immunosuppressor, which can be further explored for the development of potent immunosuppressor.

The premise of the present investigation was to evaluate the detailed anti-inflammatory properties of chlorogenic acid (CGA) and to delineate the possible mode of action. To explore the anti-inflammatory profile, we evaluated the effect of CGA on TNF-alpha expression (in vitro); carrageenan induced rat paw edema and carrageenan induce pleurisy (in vivo). In our studies, CGA significantly inhibited the TNF-alpha expression, paw edema and antioxidant enzymes in livers of rats in pre-treatment schedule but failed to exert any effect when administered 1 h after carrageenan injection. CGA was also found to be safe, as confirmed by the results of acute toxicity studies and MTT assay. CGA also caused reduction in total leucocytes count most probably by inhibiting neutrophils, but could not alter mononuclear cells count in carrageenan induced pleurisy. Inhibition of exudation was evidenced by the less exudate formation in CGA treated animals, which may be due to decrease in vascular permeability which was further confirmed in acetic acid induced vascular permeability model in mice where significant decrease in vascular permeability was observed. CGA was highly effective in reducing the arachidonic acid metabolites, nitric oxide and pro-inflammatory cytokines production in a dose dependent manner and in some conditions effect observed was almost comparable to ibuprofen. Result of the present investigation shows the anti-inflammatory effects of CGS in different models.

Despite chlorogenic acid (CGA) being widely present in nature, particularly in the human diet, there is very little information regarding its pharmacological activities. The present investigation was carried out to investigate the antiarthritic activities of this compound in adjuvant induced-arthritis in male Wistar rats, and to explore the underlying mechanisms of actions in view of immunological responses. We observed that CGA effectively controlled the total (CD3) and differentiated (CD4 and CD8) T cells count at the dose of 40?mg/kg. We also assessed the effect on co-stimulatory molecules (CD28, CD80/86) and found that CGA efficiently suppressed CD80/86 but failed to bring any changes in the CD28 count, whereas ibuprofen (standard drug) resulted in highly significant inhibition of both. We next examined the effect on CD4+ T cells specific Th1/Th2 cytokines by flow cytometry and observed that CGA suppressed the Th1 cytokines in a highly significant manner but elevated Th2 cytokines with dose dependence. Results of the present investigation suggest that CGA is a potent antiarthritic agent. Copyright (c) 2011 John Wiley & Sons, Ltd.

Many herbs and spices are known to modulate the immune system and have been shown to restore the immunity in immuno-compromised individuals. Spices generally used to increase the taste and flavor of food also has the history of usage as an ayurvedic medicine. Therefore to explore the health modulating effects of Cuminum cyminum and to identify the active compound, immunomodulatory properties were evaluated using flowcytometry and ELISA in normal and immune-suppressed animals. C. cyminum and compound 1 stimulated the T cells and Th1 cytokines expression in normal animals. Swiss albino mice subjected to Cyclosporine-A induced immune-suppression were dosed orally with C. cyminum (25, 50, 100 and 200 mg/kg) on consecutive days. The results showed that administration significantly increased T cells (CD4 and CD8) count and Th1 predominant immune response in a dose dependent manner thereby suggesting immunomodulatory activity through modulation of T lymphocytes expression. In restraint stress induced immune-suppressed animals, compound 1 countered the depleted T lymphocytes, decreased the elevated corticosterone levels and size of adrenal glands and increased the weight of thymus and spleen. Based on the data we may conclude that C. cyminum is a potent immunomodulator and may develop as a lead to recover the immunity of immuno-compromised individuals.

OBJECTIVE:To investigate the immunosuppressive potential of Pluchea lanceolata 50% ethanolic extract (PL) and its bioactive chloroform fraction (PLC). MATERIALS AND METHODS:Preliminary screening of the Pluchea lanceolata 50% ethanolic extract (PL) was carried out with basic models of immunomodulation, such as, the humoral antibody response (hemagglutination antibody titers), cell-mediated immune response (delayed-type hypersensitivity), skin allograft rejection test, in vitro (C. albicans method), and in vivo phagocytosis (carbon clearance test). The extract was then fractionated with chloroform, n-butanol, and water to receive the respective fractions by partitioning. These fractions were employed for flow cytometry to study the T-cell specific immunosuppressive potential of these fractions. RESULTS:Oral administration of PL at doses of 50 to 800 mg/kg in mice, with sheep red blood cells (SRBC) as an antigen, inhibited both humoral and cell-mediated immune responses, as evidenced by the production of the circulating antibody titer and delayed-type hypersensitiviy reaction results, respectively, and the immune suppression was statistically significant (P < 0.01) in Balb/C mice. PL also decreased the process of phagocytosis both in vitro (31.23%) and ex vivo (32.81%) and delayed the graft rejection time (30.76%). To study the T-cell-specific activities, chloroform, n-butanol, and water fractions from P. lanceolata were tested for T-cell specific immunosuppressive evaluation, wherein only the chloroform fraction (PLC) showed significant (P < 0.01) suppression of CD8+ / CD4+ T-cell surface markers and intracellular Th1 (IL-2 and IFN-(Y)) cytokines at 25 - 200 mg/kg p.o. doses. PLC, however, did not show significant suppression of the Th2 (IL-4) cytokine. CONCLUSION:The findings from the present investigation reveal that P. lanceolata causes immunosuppression by inhibiting Th1 cytokines.

Purpose: To investigate the T cell inhibition potential of 50% ethanol extract of Cyperus scariosus (CS) and its bioactive chloroform fraction (CSC).Methods: The preliminary screening of the extract was carried out by humoral antibody response and delayed-type hypersensitivity models employing sheep red blood cells (SRBC) as the antigen. Further, the extract was studied by skin allograft rejection test, and phagocytosis - in vitro and ex vivo-by C. albicans method and carbon clearance test, respectively. The extract was fractionated with chloroform, n-butanol and water, and then used to investigate the T-cell specific immunosuppressive potential of these fractions by flow cytometry.Results: On p.o. administration, CS inhibited both humoral and cell-mediated immune responses significantly (p < 0.01) by suppressing primary (26.8 %) and secondary (29.7 %) antibody titres, and also inhibited cell-mediated delayed type hypersensitivity (DTH) immune response (45.9 %) at 600 mg/kg dose, phagocytosis-both in vitro (37.4 %) and ex vivo (37.8 %) - and delayed the graft rejection time (45.8%), thus confirming marked immunosuppression. Out of the three isolated fractions, only the chloroform fraction significantly (p < 0.01) suppressed CD8+/ CD4+ T cell surface markers (14.0/25.3 %) and intra-cellular Th1 cytokines, viz, IL-2 (34.4 %), and IFN-gamma (34.7 %), compared to cyclosporine-A (5), a standard T cell inhibitor (53.6 %) which was given to Balb/C mice at 200 mg/kg dose. CSC did not significantly (p < 0.01) suppress Th2 (IL-4) system.Conclusion: The findings from this investigation reveal that C. scariosus causes immunosuppression by inhibiting Th1 cytokines.