Adaptive grey model (AGM) approach for judgemental forecasting in short-term manufacturing demand.

The covid-19 pandemic has created problems in every manufacturing sector and has posed considerable challenges to pharmaceutical, healthcare, and sanitation companies. The challenges faced are particularly daunting for pharmaceutical companies producing vaccines with ever-growing demand and shorter and shorter deadlines to fulfill them. Further, due to the vaccine's novelty and unprecedented demand, there is a lack of any available data on which traditional forecasting methods can be used. In this paper, we attempt to propose a solution by utilizing the Grey Systems Theory, particularly the AGM (1, 1) model, which has been used to significant effect for problems involving uncertain / lack of data to forecast the demand for vaccines. The experimental results obtained showed that our proposed model successfully generated accurate forecasts with a small dataset and minimal error. Additionally, judgmental forecasting has been used to qualitatively assess the future scope of vaccine manufacturing as well as the use cases of the model. We can thus effectively say proposed AGM (1,1) model is a lucid method to forecast the demand for vaccines.

Correlating work hardening with co-activation of stacking fault strengthening and transformation in a high entropy alloy using in-situ neutron diffraction.

Transformation induced plasticity (TRIP) leads to enhancements in ductility in low stacking fault energy (SFE) alloys, however to achieve an unconventional increase in strength simultaneously, there must be barriers to dislocation motion. While stacking faults (SFs) contribute to strengthening by impeding dislocation motion, the contribution of SF strengthening to work hardening during deformation is not well understood; as compared to dislocation slip, twinning induced plasticity (TWIP) and TRIP. Thus, we used in-situ neutron diffraction to correlate SF strengthening to work hardening behavior in a low SFE Fe40Mn20Cr15Co20Si5 (at%) high entropy alloy, SFE ~ 6.31 mJ m-2. Cooperative activation of multiple mechanisms was indicated by increases in SF strengthening and γ-f.c.c. → ε-h.c.p. transformation leading to a simultaneous increase in strength and ductility. The present study demonstrates the application of in-situ, neutron or X-ray, diffraction techniques to correlating SF strengthening to work hardening.

Nanoindentation behavior of high entropy alloys with transformation-induced plasticity.

Nanoindentation of three metastable dual-phase high entropy alloys (HEAs) was performed to obtain their inherent elastoplastic deformation responses. Excellent combination of hardness and elastic modulus in as-cast condition confirmed that, their inherently higher strength compared to other HEAs reported in literature, can be attributed to alloy chemistry induced phase stability. Further, hardness of 8.28 GPa combined with modulus of 221.8 GPa was obtained in Fe-Mn-Co-Cr-Si-Cu HEA by annealing the as-cast material, which is the best hardness-modulus combination obtained to date in HEAs from nanoindentation. On the other hand, although Fe-Mn-Co-Cr-Si HEA showed lower hardness and modulus than Fe-Mn-Co-Cr-Si-Al and Fe-Mn-Co-Cr-Si-Cu HEAs, the former alloy exhibited the highest strain rate sensitivity, as determined from tests performed at five different strain rates. The three alloys also had subtle differences in incipient plasticity and elastoplastic behavior, while retaining similar levels of hardness; and nanoindentation response showed microstructural dependence in friction stir processed, annealed and tensile-deformed specimens. Thus, the study highlighted that while higher strength was achieved by designing a class of HEAs with similar composition, any of the individual alloys can be tuned to obtain enhanced properties.

Extremely high strength and work hardening ability in a metastable high entropy alloy.

Design of multi-phase high entropy alloys uses metastability of phases to tune the strain accommodation by favoring transformation and/or twinning during deformation. Inspired by this, here we present Si containing dual phase Fe42Mn28Co10Cr15Si5 high entropy alloy (DP-5Si-HEA) exhibiting very high strength (1.15 GPa) and work hardening (WH) ability. The addition of Si in DP-5Si-HEA decreased the stability of f.c.c. (γ) matrix thereby promoting pronounced transformation induced plastic deformation in both as-cast and grain refined DP-5Si-HEAs. Higher yet sustained WH ability in fine grained DP-5Si-HEA is associated with the uniform strain partitioning among the metastable γ phase and resultant h.c.p. (ε) phase thereby resulting in total elongation of 12%. Hence, design of dual phase HEAs for improved strength and work hardenability can be attained by tuning the metastability of γ matrix through proper choice of alloy chemistry from the abundant compositional space of HEAs.

Morphology controlled graphene-alloy nanoparticle hybrids with tunable carbon monoxide conversion to carbon dioxide.

Selective oxidation of CO to CO2 using metallic or alloy nanoparticles as catalysts can solve two major problems of energy requirements and environmental pollution. Achieving 100% conversion efficiency at a lower temperature is a very important goal. This requires sustained efforts to design and develop novel supported catalysts containing alloy nanoparticles. In this regard, the decoration of nanoalloys with graphene, as a support for the catalyst, can provide a novel structure due to the synergic effect of the nanoalloys and graphene. Here, we demonstrate the effect of nano-PdPt (Palladium-Platinum) alloys having different morphologies on the catalytic efficiency for the selective oxidation of CO. Efforts were made to prepare different morphologies of PdPt alloy nanoparticles with the advantage of tuning the capping agent (PVP - polyvinyl pyrollidone) and decorating them on graphene sheets via the wet-chemical route. The catalytic activity of the G-PdPt hybrids with an urchin-like morphology has been found to be superior (higher % conversion at 135 °C lower) to that with a nanoflower morphology. The above experimental observations are further supported by molecular dynamics (MD) simulations.

Enhanced strength and ductility in a friction stir processing engineered dual phase high entropy alloy.

The potential of high-entropy alloys (HEAs) to exhibit an extraordinary combination of properties by shifting the compositional regime from the corners towards the centers of phase diagrams has led to worldwide attention by material scientists. Here we present a strong and ductile non-equiatomic HEA obtained after friction stir processing (FSP). A transformation-induced plasticity (TRIP) assisted HEA with composition Fe50Mn30Co10Cr10 (at.%) was severely deformed by FSP and evaluated for its microstructure-mechanical property relationship. The FSP-engineered microstructure of the TRIP HEA exhibited a substantially smaller grain size, and optimized fractions of face-centered cubic (f.c.c., γ) and hexagonal close-packed (h.c.p., ε) phases, as compared to the as-homogenized reference material. This results in synergistic strengthening via TRIP, grain boundary strengthening, and effective strain partitioning between the γ and ε phases during deformation, thus leading to enhanced strength and ductility of the TRIP-assisted dual-phase HEA engineered via FSP.

Extreme creep resistance in a microstructurally stable nanocrystalline alloy.

Nanocrystalline metals, with a mean grain size of less than 100 nanometres, have greater room-temperature strength than their coarse-grained equivalents, in part owing to a large reduction in grain size. However, this high strength generally comes with substantial losses in other mechanical properties, such as creep resistance, which limits their practical utility; for example, creep rates in nanocrystalline copper are about four orders of magnitude higher than those in typical coarse-grained copper. The degradation of creep resistance in nanocrystalline materials is in part due to an increase in the volume fraction of grain boundaries, which lack long-range crystalline order and lead to processes such as diffusional creep, sliding and rotation. Here we show that nanocrystalline copper-tantalum alloys possess an unprecedented combination of properties: high strength combined with extremely high-temperature creep resistance, while maintaining mechanical and thermal stability. Precursory work on this family of immiscible alloys has previously highlighted their thermo-mechanical stability and strength, which has motivated their study under more extreme conditions, such as creep. We find a steady-state creep rate of less than 10(-6) per second-six to eight orders of magnitude lower than most nanocrystalline metals-at various temperatures between 0.5 and 0.64 times the melting temperature of the matrix (1,356 kelvin) under an applied stress ranging from 0.85 per cent to 1.2 per cent of the shear modulus. The unusual combination of properties in our nanocrystalline alloy is achieved via a processing route that creates distinct nanoclusters of atoms that pin grain boundaries within the alloy. This pinning improves the kinetic stability of the grains by increasing the energy barrier for grain-boundary sliding and rotation and by inhibiting grain coarsening, under extremely long-term creep conditions. Our processing approach should enable the development of microstructurally stable structural alloys with high strength and creep resistance for various high-temperature applications, including in the aerospace, naval, civilian infrastructure and energy sectors.

Comparative efficacy of various toxoids against salmonellosis in poultry.

An attempt was made to develop a vaccine against salmonellosis in poultry by formalizing the Salmonella toxins (enterotoxin plus cytotoxins) that have been found to be the main virulent products of the organisms. Formalized (FT) and carbonated (CT) toxoids were prepared from partially purified toxins of Salomella enteric subspecies enterica ser. Weltevreden (BM-1643) and S. enterica ser. Gallinarum (L-19/a). There was no mortality in birds vaccinated with formalized toxoid of serovar Weltevredenplus Freund's complete adjuvant (FCA) following homologous or heterologous (S. enterica ser. Gallinarum and S. enterica ser. Typhimurium) challenges. Protection ranged from 50% to 83.3% in thegroups immunized with other preparations of S. enterica ser. Weltevreden, i.e. with FT without FCA or with CT with or without FCA. Formalized toxoid prepared from S. entrica ser. Gallinarum (FTSG) toxins given with FCA afforded 100% protection against homologous challenge, but not against heterologous serovars. In the control group. only 16.7% of the birds survived in a subgroup challenged with S. enterica ser. Gallinarum. and none withstood challenge with S enterica ser. Weltevreden or S. enterica ser. Typhimurium. No untoward reactions were observed in any of the immunized groups. Thus, the vaccine was considered to be potent and safe.

Breast metastasis of cervical carcinoma diagnosed by fine needle aspiration cytology. A case report.

BACKGROUND: Metastatic disease of the breast is often an unexpected diagnosis in a female presenting with a breast mass. The most common metastatic cancer to involve the breast is melanoma. Among gynecologic tumors, the most common primary is ovarian carcinoma. Carcinoma of the cervix metastasizing to the breast is extremely rare. CASE: A 45-year-old female developed multiple bilateral breast masses during a course of radiotherapy for carcinoma of the cervix. Cytologic smears of the breast masses revealed adenocarcinomatous cells as well as keratinizing and nonkeratinizing malignant squamous cells, consistent with a histopathologic diagnosis of metastasizing adenosquamous carcinoma of the breast from primary cervical cancer. CONCLUSION: Fine needle aspiration cytology diagnosis of malignancy metastatic to the breast is important to differentiate it from a second primary tumor and avoid an unnecessary mastectomy.

Antibody response to phenolic glycolipid I and Mycobacterium w antigens and its relation to bacterial load in M. leprae-infected mice and leprosy patients.

Twenty-six inbred BALB/cBy mice were infected with live Mycobacterium leprae by injecting 6 x 10(3) bacilli in the hind footpad. Bleeds were collected at monthly intervals. After 6 months, acid-fast bacilli (AFB) were harvested monthly from the footpad of mice. The sera were analysed in enzyme immunoassay for antibodies against phenolic glycolipid I (PGL-I) of M. leprae and antigens of Mycobacterium w (M. w); 21 out of 26 (80.7%) mice demonstrated the presence of antibodies against PGL-I and M. w . Anti-M. w antibodies appeared slightly earlier than did anti-PGL-I antibodies. The titre of anti-M. w antibodies was higher than that of anti-PGL-I antibodies. The mice giving a positive antibody response had more than 7 x 10(5) AFB/footpad. The coefficient of correlation (r) between the number of AFB and antibody titres at the time of harvest was 0.566 for PGL-I and 0.628 for M. w. The value of r for bacterial index and antibody titres in 188 leprosy patients was 0.510 for PGL-I and 0.418 for M. w; these values were statistically significant (P < 0.001). The decrease in bacterial index and antibody titres in treated lepromatous leprosy patients correlated with increase in the duration of chemotherapy. The measurement of anti-PGL-I antibodies of IgM class may serve as an adjunct to skin biopsy and skin-slit smear for serial monitoring of the bacterial load in the course of chemotherapy in leprosy control programmes.

Accessory cell heterogeneity in lepromatous leprosy; dendritic cells and not monocytes support T cell responses.

Dendritic cell (DC)-enriched cell populations from anergic lepromatous leprosy (LL) patients were found to be several-hundred-fold more efficient than monocytes (MO) in promoting antigen-induced T cell responses in autologous accessory + T cell cultures. Whereas, the use of autologous monocytes over a wide concentration range failed to stimulate Mycobacterium leprae-induced T cell proliferation, DC at concentrations as low as 0.1% induced significant proliferation in 9/15 and interferon gamma production in 14/15 LL patients. Four of the LL patients who failed to show proliferation were, however, able to secrete interferon gamma in the same T cell + DC co-cultures. DC were able to present particulate leprae antigens to autologous T cells. This preference for DC as an accessory cell was not shown when the cross-reacting antigen PPD was used in parallel co-cultures. Though tuberculoid leprosy patients showed some improvement in T cell proliferation with DC as compared to MO constituted co-cultures, this was not statistically significant. These results suggest that there is a heterogeneity in accessory cell requirement across the leprosy spectrum and that many lepromatous patients possess M. leprae-reactive functional T cells.

The nature and kinetics of a delayed immune response to purified protein derivative of tuberculin in the skin of lepromatous leprosy patients.

We have analyzed the nature and kinetics of a delayed, cell-mediated immune response to a purified protein derivative of tuberculin (PPD) in the skin of 154 naturally sensitized patients with lepromatous leprosy. After the intradermal injection of 5 U of PPD, biopsies were taken at 1-21 d and studied for the composition, extent, persistence, and organization of the emigratory cell response by light and electron microscopy. Induration of positive sites occurred promptly, reached a maximum diameter at 4 d, displayed a major extravasatory element, and was evident for as long as 21 d. The cellularity of the site exhibited a biphasic course, reached a maximum at 7 d, involved as much as 70% of the dermis and millions of new cells, and was elevated threefold above preinjection levels at 21 d. The emigratory cells were limited to T cells and circulating monocytes. T cells were more evident as they entered a preexisting lepromatous lesion containing parasitized macrophages and only occasional T cells many of the CD8+ phenotype. The predominant emigratory T cell was CD4+ although CD8+ cells were in evidence. The CD4/CD8 ratio of the lesions started at less than unity and in two distinct steps reached levels as high as 5:1. In most sites CD4+ cells were in the majority at 21 d. A well-defined granulomatous response with epithelioid and giant cells was apparent at 4 d, reached a maximum at 7 d, and involved all PPD sites at this time point. The generation of these differentiated mononuclear phagocytes from newly emigrated monocytes was never observed in the underlying lepromatous lesion but is a constant feature of the tuberculoid leprosy response. Epidermal thickening and keratinocyte proliferation, sequellae of the dermal reaction, reached a maximum at 7 d and gradually resolved by 3 wk. A constant feature of the PPD response was the extensive destruction of preexisting macrophages containing Mycobacterium leprae bacilli or their products. This was associated with the presence of and intimate contact with highly polarized lymphoid cells of unknown phenotype. Cell destruction did not involve other elements of the dermis and spared parasitized Schwann cells. Newly emigrated T cells and monocytes were never seen within the perineural sheath in contact with neural elements. It appears that a single antigenic stimulus leads to a very long-term, defined series of events with distinct temporal patterns. It includes waves of emigratory T cells, the maturation and organization of monocytes, the generation of killer cells, and the extensive destruction of parasitized macrophages.(ABSTRACT TRUNCATED AT 400 WORDS)

Type 1 reactions in leprosy--heterogeneity in T-cell functions related to the background leprosy type.

Nineteen each of paucibacillary borderline tuberculoid (BT) and multibacillary borderline borderline (BB)/borderline lepromatous (BL) leprosy patients undergoing type 1 reactions were compared with nonreactional stable patients of the appropriate leprosy type. In the BT reactional group, both phytohemagglutinin-induced and, more importantly, antigen-induced lymphoproliferation was reduced in 80%-90% of the patients. On the other hand, leukocyte migration inhibition was reduced in 40% and remained unchanged in the others. Suppressor-cell activity as evaluated by a costimulant assay was also reduced in a majority of the reactional BT individuals. In contrast, the bacilliferous BB and BL patients in reaction showed significant general improvement in leukocyte migration inhibition (p less than 0.001) and antigen-induced lymphoproliferation (p less than 0.05) as compared to the expected hyporesponsive/anergic uncomplicated BB-BL patients. Suppressor-cell activity also recovered during the reactional phase. However, no significant differences were observed in either of the reactional or stable leprosy types in the numbers of total T cells (OKT3+) and their subsets as defined by OKT4+ (helper/inducer) and OKT8+ (suppressor/cytotoxic) functional phenotypes. Moreover, during type 1 reactions the 48-hr delayed-type hypersensitivity (DTH) responses after intradermal injection of Mycobacterium leprae antigens continued to reflect the background leprosy type rather than the functional perturbations in the circulating T cells. Only a marginal increase in DTH was observed in some BT reactional individuals. No consistent pattern in the above in vitro T-cell-related responses was discernable in the same individuals 4-6 months after subsidence of reactions. The clinical entity of type 1 reactions encompassing paucibacillary and multibacillary leprosy shows a heterogeneity/dichotomy in T-cell responses which may reflect different immunological mechanisms underlying the reactional state.

Comparison of radiometric macrophage assay and fluorescein diacetate/ethidium bromide staining for evaluation of M. leprae viability.

Earlier studies from our laboratory reported that a radiometric Mycobacterium leprae resident macrophage assay was a useful in vitro indicator of bacillary viability with good correlation with the established mouse foot pad model. The present study compares our assay with the recently described fluorescein diacetate/ethidium bromide (FDA/EB) method. M. leprae extracted from the dermal lesions of 73 bacilliferous leprosy patients were tested concurrently by both techniques. Good correlation (r = 0.52, p less than 0.001) was found between the radiometric assay evaluating DNA synthesis and the FDA/EB staining reflecting the presence of active esterase enzyme. In addition, the utility of the FDA/EB staining in the monitoring of therapy was established. Twenty-two patients treated for greater than 1 year showed lower numbers of green fluorescing bacilli when compared to 19 untreated or short-term-treated individuals.

Phenolic glycolipid-I of Mycobacterium leprae induces general suppression of in vitro concanavalin A responses unrelated to leprosy type.

Using a costimulant assay, in vitro Con A responses of patients across the leprosy spectrum were found to be markedly suppressed by phenolic glycolipid-I (PGL-I), a unique antigen of M. leprae. The degree of inducible suppression as well as the number of leprosy patients showing suppression of mitogenic responses was higher with PGL-I as compared with integral M. leprae (p less than 0.05 to less than 0.01). Both untreated lepromatous (60%) as well as tuberculoid leprosy (67%) patients showed significant suppression ranging from 13 to 64% and 12 to 79%, respectively. Thus, PGL-I appears to have a universal suppressive effect on Con A responses and is unlikely to play a central role in determining the leprosy spectrum.

Cutaneous Involvement in Acute Meningococcemia (Study of an Epidemic in Delhi).

Thirty (88.2%) out of 34 children with skin lesions were observed during the recent epidemic of meningococcus group A infection in Delhi. Purpuric lesions were the commonest (60%), maculo-papular in 26-67% and faint pink macules'm 13.33% Conjunctivae were affected m 3. These eruptions appeared within 6 hours: ulcers and gangrene appeared after 7 days in one child. Severe vascular damage was seen on histoplthology of the ulcers as compared to the early lesions. Gangrene of the extremities developed during the recovery phase when all other signs of the disease had subsided.

An epidemiological study of scabies in a rural community in India.

An epidemiological survey for scabies was conducted in a rural community of 2771 persons among 404 households living in 238 houses. Prevalence rates were 13% by population and 30.9% by household. Each index case was responsible, on average, for the spread of infection to 1.9 persons in affected households. Significantly lower rates of secondary attack and transmissibility were observed among the more prosperous villagers. The proportion of infected households increased linearly with household size. The prevalence was highest in those aged up to 19 years, both sexes being affected equally. An average morbidity duration for scabies was 64.5 days; 16.3% of the patients showed secondary pyogenic infection of the skin.

Some observations on default among leprosy patients.

The problem of default or irregularity in taking the medicine is a great hinderance to the eradication of the disease. An attempt has been made here to judge this problem from various angles and to pin point the factors leading to default. A cohort of 253 patients have been comprehensively interviewed and the results have been analysed statistically.