Cold Spray: Over 30 Years of Development Toward a Hot Future.

Cold Spray (CS) is a deposition process, part of the thermal spray family. In this method, powder particles are accelerated at supersonic speed within a nozzle; impacts against a substrate material triggers a complex process, ultimately leading to consolidation and bonding. CS, in its modern form, has been around for approximately 30 years and has undergone through exciting and unprecedented developmental steps. In this article, we have summarized the key inventions and sub-inventions which pioneered the innovation aspect to the process that is known today, and the key breakthroughs related to the processing of materials CS is currently mastering. CS has not followed a liner path since its invention, but an evolution more similar to a hype cycle: high initial growth of expectations, followed by a decrease in interest and a renewed thrust pushed by a number of demonstrated industrial applications. The process interest is expected to continue (gently) to grow, alongside with further development of equipment and feedstock materials specific for CS processing. A number of current applications have been identified the areas that the process is likely to be the most disruptive in the medium-long term future have been laid down.

Intermetallic Phase Evolution of Cold-Sprayed Ni-Ti Composite Coatings: Influence of As-Sprayed Chemical Composition.

Owing to low-temperature deposition conditions and high deposition rate, cold spray offers unique advantages in manufacturing a wide variety of metallic and composite coatings including metal matrix composites produced from physically blended powders. One of the challenges of producing composite coatings using cold spray is the deviation of coatings composition from the blended feedstock powder composition. This is of utmost importance as it affects the composition and phase evolution of intermetallic forming coatings during post spray heat treatment. In this work, cold spray of composite Ni-Ti coatings and formation of intermetallics from post spray heat treatment were investigated as a first step to examine the potential of producing equiatomic bulk Ni-Ti by cold spray. Three different physically blended Ni and Ti powders mixtures were sprayed on titanium substrates to address the coating composition variation from the blended feedstock powder and study its influence on phase evolution during post spray heat treatment. High-density and well-dispersed composite coatings were achieved for each case. EDS analysis revealed as-sprayed coatings with 10.5, 35.9 and 56.9 at.% Ni (and with balanced Ti ratios) from the three powder mixtures. Annealing treatments were conducted at 400, 500 and 900 °C for 1 and 2 h and comparative studies of the intermetallic compound formations were carried out. Microstructural investigation showed that all three equilibrium intermetallics phases of binary Ni-Ti phase diagram (Ni3Ti, Ti2Ni and NiTi) formed in the two Ni-rich composite coatings with NiTi phase being maximum in the coating with the closest composition to equiatomic ratio while only Ti2Ni phase formed in the Ti-rich coating after annealing. Thermal etching analysis of coatings showed that NiTi phase forms with a gradient microstructure from Ti splats boundary toward the center of splats, which is attributed to the grain refinement of CS samples at splat boundary and intermetallic nucleation mechanism.

Serial interval and time-varying reproduction number estimation for COVID-19 in western Iran.

There is no report on the serial interval (SI) of coronavirus disease 2019 (COVID-19) in Iran, the present report aims to estimate the SI and time-varying R of COVID-19 in western Iran. In this study, there were 1477 confirmed, probable and suspected cases of severe acute respiratory syndrome coronavirus 2 for Kermanshah from 22 February to 9 April. The close contacts of the confirmed cases were identified using telephone follow up of patients and their contacts. The SI distribution was used as an alternative. We fitted different models using the clinical onset dates of patients with their close contact (infector-infectee). Also, we applied a 'serial interval from sample' approach as a Bayesian methodology for estimating reproduction number. From 22 February to 29 March, 247 COVID-19 cases were confirmed by RT-PCR. Close contact between 21 patients (21 infector-infectee pairs), including 12 primary cases and 21 secondary cases, was confirmed. The mean and standard deviation of the SI were estimated as 5.71 and 3.89 days. The R varied from 0.79 to 1.88 for a 7-day time-lapse and ranged from 0.92 to 1.64 for a 14-day time-lapse on raw data. Also, the R varied from 0.83 to 1.84 for 7-day time-lapse and from 0.95 to 1.54 for a 14-day time-lapse using moving average data, respectively. It can be concluded that the low reproduction number for COVID-19 in Kermanshah province is an indication of the effectiveness of preventive and interventive programmes such as quarantine and isolation. Consequently, continuing these preventive measures is highly recommended.

Bajos niveles de inhibidores de la coagulación: un factor de alto riesgo trombogénico en pacientes talasémicos / Low levels of coagulation inhibitors: a high-risk thrombotic factor in thalassemic patients

ANTECEDENTES Y OBJETIVO: La β-talasemia mayor (β-TM) se define como una enfermedad hereditaria relacionada con las células rojas sanguíneas. En los pacientes adultos, los eventos trombóticos se asocian con la talasemia. Así, el objetivo de esta investigación fue examinar algunos de los parámetros hemostáticos, incluyendo la antitrombina III (AT-III), la proteína C (PRC) y la proteína S (PRS), en pacientes β-TM. MÉTODOS: Se seleccionó a 30pacientes β-TM remitidos para un ingreso de seguimiento de rutina en la clínica de talasemia del Centro Especial de Enfermedades Kerman, junto con otros 30 sujetos sanos. Tras el registro y 3 semanas después de la última transfusión, se recogieron especímenes de sangre periférica, y se midió la concentración plasmática de AT-III, PRC y PRS. RESULTADOS: Hemos observado que la concentración de inhibidores naturales de la coagulación (PRC y PRS) estaba ligeramente disminuida en los pacientes β-TM (p < 0,05), mientras que el nivel plasmático de AT-III no era muy diferente en los pacientes β-TM cuando se los comparaba con los sujetos sanos. CONCLUSIÓN: Conforme a los hallazgos obtenidos en el presente trabajo, podríamos considerar los cambios significativos en las PRC, PRS y AT-III, que se observan en pacientes β-TM multitransfundidos, como factores de riesgo críticos para el desarrollo de eventos tromboembólicos futuros a lo largo de su vida

BACKGROUND AND AIM: The β-thalassemia major (β-TM) is defined as a hereditary red blood cell-related disease. Thrombotic events are associated with thalassemia in adult patients. Thus, the present investigation was aimed to examine some hemostatic parameters, including anti thrombin-III (AT-III), protein-C (PRC) and protein-S (PRS) in β-TM patients. METHODS: Thirty B-TM patients who referred for routine follow-up admission to the thalassemia clinic of Kerman Special Disease Center alongside with 30 healthy subjects were selected and enrolled in the present study. Further registration, the peripheral blood specimens were collected after 3 weeks of last transfusion and then the plasma concentrations of AT-III, PRC and PRS were measured in them. RESULTS: We have observed that the concentrations of natural coagulation inhibitors (PRC and PRS) were significantly attenuated in β-TM patients (P<0.05), while the plasma level of AT-III was not remarkably differed in β-TM patients in compare to healthy subjects. CONCLUSION: According to the findings of present work, significant changes in the PRC, PRS and AT-III which could be observed in multi transfused β-TM patients may attribute as critical risk factors for the development of upcoming thromboembolic events in their future life

Low levels of coagulation inhibitors: A high-risk thrombotic factor in thalassemic patients. / Bajos niveles de inhibidores de la coagulación: un factor de alto riesgo trombogénico en pacientes talasémicos.

BACKGROUND AND AIM: The ß-thalassemia major (ß-TM) is defined as a hereditary red blood cell-related disease. Thrombotic events are associated with thalassemia in adult patients. Thus, the present investigation was aimed to examine some hemostatic parameters, including anti thrombin-III (AT-III), protein-C (PRC) and protein-S (PRS) in ß-TM patients. METHODS: Thirty B-TM patients who referred for routine follow-up admission to the thalassemia clinic of Kerman Special Disease Center alongside with 30 healthy subjects were selected and enrolled in the present study. Further registration, the peripheral blood specimens were collected after 3 weeks of last transfusion and then the plasma concentrations of AT-III, PRC and PRS were measured in them. RESULTS: We have observed that the concentrations of natural coagulation inhibitors (PRC and PRS) were significantly attenuated in ß-TM patients (P<0.05), while the plasma level of AT-III was not remarkably differed in ß-TM patients in compare to healthy subjects. CONCLUSION: According to the findings of present work, significant changes in the PRC, PRS and AT-III which could be observed in multi transfused ß-TM patients may attribute as critical risk factors for the development of upcoming thromboembolic events in their future life.

Potential use of melatonin supplementation to protect vitrified testicular grafts from hypoxic-ischaemic damage.

This study aimed to assess the morphological changes in neonate vitrified testicular grafts after host treatment with melatonin. Neonate vitrified testes, candidates for transplantation to treated and nontreated groups receiving melatonin, were thawed in media containing or not containing 100 µm melatonin. Following transplantation, melatonin (20 mg kg(-1) per day) and saline were given to the treated and nontreated groups for up to 9 weeks. The testicular status was assayed by terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-biotin nick-end labelling TUNEL, semi-thin section and ultra-structure studies. Chi-squared test was used to compare categorical variables between the groups. Overall, the degenerative and apoptosis changes in the vitrified testis parenchyma were not significant. However, atrophic seminiferous cords and jumbled appearance of the interstitial space were more often observed in the nontreated group than in the treated ones. Semi-thin sections showed that the germinal epithelium was taken in a normal arrangement on the testicular grafts of both groups. Nevertheless, ultrastructural analysis revealed that the characteristics of interstitial space cells, basement membrane BM and epithelial cells of seminiferous tubules in the treated group were better than those in the nontreated group. The study revealed a beneficial effect of melatonin on vitrified neonatal testes and after that, on restoring testicular grafts.

Beta3 integrin expression within uterine endometrium and its relationship with unexplained infertility.

The aim of this study was to investigate whether the endometrium of women with unexplained infertility differs in the presence of the beta 3 (beta3) integrin molecule from the endometrium of normal fertile women. In a retrospective case-control study 30 endometrial biopsies from hysterectomies with nonendometrial pathology and 30 endometrial samples from women with a history of unexplained infertility were collected during the window of implantation. Immunohistochemically staining with a monoclonal antibody against beta3 integrin subunit in endometrial biopsies was performed and then assessed semiquantitively by microscope on different endometrial compartments including glandular epithelial cells, vessels, lymphocytes, macrophages and stromal cells. Chi-square test was used to compare the expression and defect of beta3 integrin subunit between two groups. The results showed that beta3 integrin molecules were present in fertile and infertile endometrial uterine tissues. The majority of glandular epithelial cells expressed beta3 integrin in fertile endometrium. However, the endometrial expression of beta3 integrin was reduced significantly in infertile endometrium during the window of implantation (p < 0.05). A few numbers of vessels and stromal cells expressed beta3 integrin molecule with no statistical significance between the two groups. In conclusion Abnormal endometrial integrin expression is a frequent finding in women with unexplained infertility. A therapeutic potential approach in improving uterine endometrium receptivity together with up-regulation of beta3 integrin in this population of women suggested.