A Cross-Sectional Comparative Study of Morbidity and Mortality of COVID-19 Disease in four Cities of Northern Khorasan Province using Ratio of Coefficient of Variation.

Background: In December 2019, the spread of a new infectious disease was reported in Wuhan, caused by a new coronavirus named COVID-19 by the World Health Organization. This study aims to compare the dispersion of COVID-19 disease among four Iranian cities in North Khorasan named Bojnord, Farooj, Jajarm, and Shirvan. Materials and Methods: This cross-sectional study includes information about the daily morbidity and mortality of COVID-19 in 1124 patients from March to May 2021. The analysis of variance method, Scheffe post hoc technique and Leven's test are used to compare the means and the variances of daily morbidity and mortality of these cities. Finally, the coefficients of variation (CVs) of the morbidity and mortality are compared. Results: The means of daily morbidity in Bojnord, Farooj, Jajarm, and Shirvan cities are 6.387, 0.946, 1.150, and 2.193, respectively. Furthermore, the means of daily mortality in Bajnourd, Farooj, Jajarm, and Shirvan are 0.763, 0.193, 0.161, and 0.290, respectively. The means and the variances of both daily mortality and morbidity are significantly different in all four cities (P < 0.05). Furthermore, CVs of daily morbidity in the cities of Bojnord, Farooj, Jajarm, and Shirvan are 0.665, 1.026, 1.032, and 0.787, respectively. The CVs of daily mortality in these cities are 1.196, 2.052, 2.468, and 1.728, respectively. The CVs of both daily mortality and morbidity are significantly different in all four cities (P < 0.05). Conclusion: The ratio of CVs is a good option for comparing the spread of COVID-19 in different regions with different means and variances.

Additive-Free and Support-Free 3D Printing of Thermosetting Polymers with Isotropic Mechanical Properties.

The democratization of thermoplastic 3D printing is rooted in the ease of processing enabled by economical melting and shaping. Thermosetting polymers, on the other hand, have not enjoyed this advantage given that thermosetting resins cannot hold their shape without cross-linking or excessive fillers, and once cross-linked, they cannot be extruded for printing. Due to this formidable challenge, thus far, 3D printing of thermosetting polymers has been limited to the photopolymerization of specialized photosensitive resins or extrusion of resins loaded with large fractions (as high as 20 wt %) of rheology modifiers. Here, we report a rheology-modifier- and photoinitiator-free process for the 3D printing of a pure commercial epoxy polymer, without any resin modification and using a conventional 3D printer. A low-cost non-Newtonian support material that switches between solid-fluid states under a nozzle shear stress enables the printing of complex 3D structures and the subsequent and ″one-step″ curing. Our results show that the one-step curing eliminates the often-compromised interlayer adhesion common in layer-by-layer 3D printing processes and results in unprecedented isotropic mechanical properties (strength, elastic modulus, tensile toughness, and strain to failure). This in-bath print and cure (IBPC) 3D printing process for thermosetting polymers is low-cost, scalable, high-speed (nozzle speeds exceeding 720 cm/min), and high-resolution (down to 220 µm filament size). We demonstrate potential applications for hobbyists, structural and aerospace components, and fiber-reinforced composites, among others.

Computational Modeling of Combination of Magnetic Hyperthermia and Temperature-Sensitive Liposome for Controlled Drug Release in Solid Tumor.

Combination therapy, a treatment modality that combines two or more therapeutic methods, provides a novel pathway for cancer treatment, as it targets the region of interest (ROI) in a characteristically synergistic or additive manner. To date, liposomes are the only nano-drug delivery platforms that have been used in clinical trials. Here, we speculated that it could be promising to improve treatment efficacy and reduce side effects by intravenous administration of thermo-sensitive liposomes loaded with doxorubicin (TSL-Dox) during magnetic hyperthermia (MHT). A multi-scale computational model using the finite element method was developed to simulate both MHT and temperature-sensitive liposome (TSL) delivery to a solid tumor to obtain spatial drug concentration maps and temperature profiles. The results showed that the killing rate of MHT alone was about 15%, which increased to 50% using the suggested combination therapy. The results also revealed that this combination treatment increased the fraction of killed cells (FKCs) inside the tumor compared to conventional chemotherapy by 15% in addition to reducing side effects. Furthermore, the impacts of vessel wall pore size, the time interval between TSL delivery and MHT, and the initial dose of TSLs were also investigated. A considerable reduction in drug accumulation was observed in the tumor by decreasing the vessel wall pore size of the tumor. The results also revealed that the treatment procedure plays an essential role in the therapeutic potential of anti-cancer drugs. The results suggest that the administration of MHT can be beneficial in the TSL delivery system and that it can be employed as a guideline for upcoming preclinical studies.

Three-Dimensional Printing of Ceramics through "Carving" a Gel and "Filling in" the Precursor Polymer.

Achieving a viable process for three-dimensional (3D) printing of ceramics is a sought-after goal in a wide range of fields including electronics and sensors for harsh environments, microelectromechanical devices, energy storage materials, and structural materials, among others. Low laser absorption of ceramic powders renders available additive manufacturing (AM) technologies for metals not suitable for ceramics. Polymer solutions that can be converted to ceramics (preceramic polymers) offer a unique opportunity to 3D-print ceramics; however, due to the low viscosity of these polymers, so far, their 3D printing has only been possible by combining them with specialized light-sensitive agents and subsequently cross-linking them layer by layer by rastering an optical beam. The slow rate, lack of scalability to large specimens, and specialized chemistry requirements of this optical process are fundamental limitations. Here, we demonstrate 3D printing of ceramics enabled by dispensing the preceramic polymer at the tip of a moving nozzle into a gel that can reversibly switch between fluid and solid states, and subsequently thermally cross-linking the entire printed part "at-once" while still inside the same gel. The solid gel, which is composed of mineral oil and silica nanoparticles, converts to fluid at the tip of the moving nozzle, allows the polymer solution to be dispensed, and quickly returns to a solid state to maintain the geometry of the printed polymer both during printing and the subsequent high-temperature (160 °C) cross-linking. We retrieve the cross-linked part from the gel and convert it to ceramic by high-temperature pyrolysis. This scalable process opens up new opportunities for low-cost and high-speed production of complex three-dimensional ceramic parts and will be widely used for high temperature and corrosive environment applications, including electronics and sensors, microelectromechanical systems, energy and structural applications.

Molecular Identification and Phylogenetic Classification of Leishmania spp. Isolated from Human Cutaneous Leishmaniasis in Iran: A Cross-sectional Study.

BACKGROUND: In Iran, both forms of cutaneous (CL) and visceral leishmaniasis (VL) have been reported; so the accurate species identification of the parasite(s) and the analysis of genetic diversity are necessary. METHODS: The smears were collected from lesions samples of 654 patients with CL, who attended local health centers in 12 provinces of Iran during 2013-2015. The smears were checked for the presence of amastigotes by light microscopy. DNA of 648 Leishmania isolates, amplified by targeting a partial sequence of ITS (18S rRNA-ITS1-5.8S rRNA-ITS2) gene. Twenty-five of all the amplicons were sequenced and analyzed with restriction fragment length polymorphism (RFLP) using the Taq1 enzyme. RESULTS: All the smears were positive microscopically. The PCR-RFLP analysis revealed that 176 (27%) CL patients were infected with L. tropica and, 478 (73%) with L. major. The dominant species in all over Iran is L. major. The sequencing results of all CL patients and RFLP analysis confirmed each other. Based on our phylogenetic tree, 25 ITS DNA sequences were grouped into two clusters representing L. major and L. tropica species. Phylogenetic tree derived from the ITS sequences supports a clear divergence between L. major from the other species. CONCLUSION: Discrimination of Iranian Leishmania isolates using ITS gene gives us this opportunity to detect, identify, and construct the phylogenetic relationship of Iranian isolates.

Molecular Identification and Intra-species Variations among Leishmania infantum Isolated from Human and Canine Visceral Leishmaniasis in Iran.

BACKGROUND: In Iran, both forms of cutaneous (CL) and visceral leishmaniasis (VL) have been re-ported; so the accurate species identification of the parasite(s) and the analysis of genetic diversity are necessary. METHODS: The investigation was conducted from 2014 to 2015 in the northwest and south of Iran, where VL is endemic (7 provinces). Blood samples of patients and infected dogs were collected and sera separated for serologic examinations (DAT, rK39). Spleen or bone marrow samples from infected dogs were also collected to confirm the infection. DNAs of 70 samples amplified by targeting a partial sequence of ITS (18S rRNA-ITS1-5.8S rRNA-ITS2) gene. All the amplicons were sequenced and analyzed with restriction fragment length polymorphism (RFLP) using the TaqI enzyme. RESULTS: The cause of all 70 VL cases, were L. infantum, so, the dominant specie is L. infantum. The sequencing results of all VL cases and RFLP analysis corroborate each other. Discrimination of Iranian Leishmania isolates using ITS gene gives us this opportunity to detect, identify and construct the phylogenetic relationship of Iranian isolates. In addition, detection and differentiation of Leishmania spp. DNA was confirmed by amplification of variable area of the minicircle kDNA (conserved sequence blocks (CSB)). CONCLUSION: Low divergence and high likelihood were seen among L. infantum isolates of human and dogs from Iran with a very slight divergence was seen between isolates from northwest and south of Iran, thus grouped in a unique clad. No correlation was observed between intraspecies divergence and geographic distribution of the isolates.

Cryptosporidium and cryptosporidiosis: The Asian perspective.

This review discusses findings of Cryptosporidium and cryptosporidiosis research in Asia and highlights the current situation of Cryptosporidium epidemiology, genetic diversity and distribution, and transmission throughout Asia taking into account all the available papers published for Cryptosporidium research in Asian countries since 2000. This effort will facilitate future research approaches and further developments in the understanding of Cryptosporidium epidemiology in Asia. The intent is to contribute to improvement in protection measures for mitigating the burden associated with this illness in the future.

Detection of Cryptosporidium and Giardia (oo)cysts by IFA, PCR and LAMP in surface water from Rasht, Iran.

BACKGROUND: Cryptosporidium and Giardia in water supplies is acknowledged as a public health problem. In the present study, we applied immunofluorescence assay (IFA), PCR and loop-mediated isothermal amplification (LAMP) for the detection of the two protozoa. METHODS: Over a period of 12 months, surface water samples were collected from two rivers in the north of Iran, and filtrated by 142 mm membrane filters. At each sampling point 10 L water were used for IFT and the10 L were analysed using molecular methods. RESULTS: In 15/40 samples, (oo)cysts were detected by one of the IFA, PCR or LAMP methods. Five samples that were Cryptosporidium-negative by IFA were positive by LAMP. A total of 10 out of 13 samples that were Giardia-positive by IFA were also positive by PCR. IFA revealed high levels of Giardia, with 1-1800 cysts and 1-16 Cryptosporidium oocysts detected per 10 L. CONCLUSION: The study reveals that the investigated water supplies were contaminated by Cryptosporidium and Giardia. The LAMP assay has advantages for detection and screening of these protozoa at relatively low concentration in water samples. The three assays applied are complimentary but no single one will give the true prevalence of these parasites in surface water samples. However, each method has its own advantages and disadvantages dependent of the aim and the study design; a combination of detection methods should be applied to discover whether water is, or is not, contaminated with (oo)cysts. This is the first report on the occurrence of (oo)cysts in Iranian surface waters to compare the results of parasite detection obtained with the different methods.