This experimental study investigates the effect of filling pattern on tensile and flexural strength and modulus of the parts printed via fused deposition modeling (FDM), 3D printer. The main downside ...of the printed products, with an FDM 3D printer, is the low strength compared to the conventional processes such as injection molding and machining. The issue stems from the low strength of thermoplastic materials and the weak bonding between deposited rasters and layers. Selection of proper filling pattern and infill percentage could highly influence the final mechanical properties of the printed products that were experimentally explored in this research work. Concentric, rectilinear, hilbert curve, and honeycomb patterns and filling percentage of 20, 50 and 100 were the variable parameters to print the parts. The results indicate that concentric pattern yields the most desirable tensile and flexural tensile properties, at all filling percentages, apparently due to the alignment of deposited rasters with the loading direction. Hilbert curve pattern also yielded a dramatic increase in the properties, at 100% filling. The dramatic increase could be mainly attributed to the promotion of strong bonding between the rasters and layers, caused by maintaining a high temperature of rasters at short travelling distances of nozzle for the hilbert curve pattern. Scanning electron microscopy (SEM) examination revealed the strong bonding between rasters and sound microstructures (less flaws and voids) for concentric and hilbert curve pattern at a high filling percentage of 100. Besides, SEM examination revealed large voids in honeycomb pattern, deemed to be responsible for its lower strength and modulus, especially at the filling percentage of 100.
Bipolar plates (BPPs) play an important role in PEM fuel cells in terms of weight and cost points of view. In this paper, the manufacturing of titanium BPPs with parallel flow field was ...experimentally and numerically studied. In this regard, a stamping die with a parallel pattern is conducted to perform the experiments. Then, the process was modeled via the finite element (FE) simulation. By comparing simulation and experiment results, it was found that the results are in good agreement and hereupon, the accuracy of the FE model was verified. To evaluate the sheet formability, a set of FE experiments was designed through the response surface methodology (RSM). The die clearance, forming velocity, and friction coefficient were considered input parameters, and the maximum thickness reduction (MTR) of the sheet was assumed to be the output. The results revealed that a lower friction coefficient causes an increase in thickness reduction and finally tearing in the formed BPPs. Moreover, changing the forming velocity has no remarkable influence on the MTR. Afterward, an Adaptive Neuro-Fuzzy Inference System (ANFIS) was trained for predicting the output of the MTR with the three mentioned inputs.
•Lmp27−/− mutant as a vaccine candidate is safe in dogs.•Lmp27−/− mutant induces protective immunity against heterologous challenge in dogs.•Lmp27−/− mutant as vaccine candidate induces protection ...against canine leishmaniasis.
Canine leishmaniasis (CanL) is an important parasitic e disease caused by Leishmania infantum and is transmitted by female phlebotomine sand flies primarily between canines and secondarily to humans. Recently, we showed that immunization with Leishmania major p27 gene knockout (Lmp27−/−) as a live attenuated vaccine was safe, induced immunogenicity, and protected against the development cutaneous and visceral leishmaniasis in mice. The p27 protein is a component of the COX protein complex which is responsible for ATP production. In this study, we analyzed the Lmp27−/− candidate vaccine potential with this regard to the safety and induction of immunogenicity and protection against CanL. Variables such a clinical manifestation, anti-Leishmania antibodies using direct agglutination test (DAT), lymphocyte proliferation, delayed-type hypersensitivity (DTH), bone marrow aspiration (BMA) and parasite burden using parasitological and molecular examinations were measured. The results demonstrated that the Lmp27−/− vaccinated group showed no clinical signs after inoculation with Lmp27−/− mutant during a 12-month follow-up, and had significantly higher T-cell responses (Lymphocyte proliferation and DTH), lower seroconversion and parasite burdens following a challenge inoculation with L. infantum after 6-mounth. In conclusion, vaccination with Lmp27−/− parasites would be safe and provide significant immunoprotectivity and efficacy against infection with wild type (WT) L. infantum.
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► Leishmania infantum infection in blood samples of 100 dogs and 100 humans by real time PCR were analyzed. ► A sensitivity of 100% and 93.9%, specificity of 96.4% and 100%, were ...found for dog and human samples, respectively. ► The highest concordance was obtained between DAT and real-time PCR results.
Zoonotic visceral leishmaniasis (VL) is endemic in northwestern Iran. Real-time PCR, conventional PCR, and the direct agglutination test (DAT) were used to diagnose Leishmania infantum infection in blood samples from 100 domestic dogs and 100 humans. Based on clinical evaluation, 82 humans and 72 dogs from the endemic area were categorized as having asymptomatic infection, DAT positive with no clinical signs of VL, or symptomatic infection, DAT positive with at least one sign of VL. Eighteen human samples containing no Leishmania antibodies (DAT−) and 28 dog DAT− sera from non-endemic areas with no history of VL constituted negative controls. All 46 DAT− samples were also negative by Dipstick rK39. Bone marrow material was used for parasitological examinations in symptomatic VL, and peripheral blood samples were used for detection of L. infantum infection using conventional PCR and real-time PCR in non-symptomatic subjects. Two DNA targets (ITS1 kDNA) were used for conventional PCR. L. infantum antibodies in sera were detected by DAT. Parasitemia was measured by real-time PCR targeting kDNA using Taqman Assay. All 72 (100%) symptomatic (38/38) and asymptomatic (34/34) dog DAT+samples, 45 of 48 (93.8%) symptomatic human DAT+ samples, and 32 of 34 (94.1%) human asymptomatic cases were identified by real-time PCR. The mean (59.19 vs 12.38 parasite equivalents/mL of blood) and median (16.15 vs 1 parasite equivalents/mL of blood) ranges of parasitemia were higher in dogs than in humans (P<0.05). The highest agreement was obtained between real-time PCR and DAT (99% in dogs and 95% in humans). Sensitivity of 100% and 93.9%, specificity of 96.4% and 100%, positive predictive values of 98.6% and 100%, and negative predictive values of 100% and 78.3% were found by real-time PCR for dog and human samples, respectively.
Canine visceral leishmaniasis (CVL) is endemic in northwestern Iran. This study aimed to compare real-time PCR, conventional PCR, and the direct agglutination test (DAT) for the diagnosis Leishmania ...infantum infection in 167 serum samples of domestic dog. Bone marrow was used for parasitological examination (smears and/or culture) in symptomatic visceral leishmaniasis, and serum was used for detection of L. infantum kinetoplast DNA (kDNA) by both conventional PCR and real-time PCR, while anti-L. infantum antibodies in sera were measured by DAT. The sera were collected from 37 symptomatic and 112 asymptomatic dogs during April to May 2011. Eighteen presumed negative samples were obtained from healthy dogs kept in non-endemic areas with no history of CVL and used as controls. All 18 samples were negative by DAT and Dipstick rK39. DAT confirmed previous exposure to L. infantum for all 149 serum samples collected from symptomatic and asymptomatic dogs in CVL endemic areas of Iran. Among the 37 symptomatic dogs, 20 (54%), 25 (67.6%), 36 (97.3%), and 37 (100%) showed L. infantum infection by parasitological methods, conventional PCR, real-time PCR, and DAT (≥1:80), respectively. Of 112 asymptomatic dogs, 79 (70.5%), 111 (99.1%), and 112 (100%) were shown to be positive by conventional PCR, and DAT (≥1:80), respectively. For ethical reasons, no asymptomatic or healthy control dogs were examined by parasitological methods. Three (16.7%) control dogs were positive by real-time PCR, but were negative by DAT, dipstick rK39, and conventional PCR methods. Parasitemia levels were measured by real-time PCR targeting kDNA using SYBR® green assay. This quantitative technique detected infection in 89.9% (150/167) of the domestic dogs that harbored L. infantum kDNA, ranging from 0.01 49 to 310.1 parasites/ml. The average was 16.60 parasites/ml. A good agreement (0.97) was found between real-time PCR and DAT at ≥1:80 titer, used as cut-off value by Kappa analysis. Thus, real-time PCR as a quantitative PCR assay on serum samples represents a valuable tool for initial diagnosis of CVL when whole blood is not available.
This study was a randomized, open label comparison that was designed to determine efficacy and safety of miltefosine as the first oral drug for the treatment of zoonotic cutaneous leishmaniasis ...caused by
Leishmania major in comparison with meglumine antimoniate. Complete clinical response was defined as 100% re-epithelialization of the lesion. Definitions of lesion cure and failure were based on both clinical and parasitological criteria two weeks after the end of treatment and clinical recovery three months after this period. Of 32 patients enrolled for miltefosine treatment 28 patients completed treatment, of which 26 were cured at three months, corresponding to a cure rate of 92.9% on a per protocol analysis, and 81.3% according to intention to treat analysis. There was one failure (3.1%), one relapse (3.1%) and four dropouts due to lack of tolerability (12.5%) during the first week of treatment. Of 31 patients who received intramuscular meglumine antimoniate (20
mg
Sb
5/kg body weight daily for 14 days) 25 were cured (83.3% on a per protocol basis, 80.6% on intention to treat basis), five failed (16.1%) and one was lost (3.2%) at 3-month follow-up. At 6-month follow-up after the end of treatment, no relapse was observed. Both regimens were tolerated but averages of nausea (32.2%) and vomiting (21.5%) were observed in patients during two weeks after initiation of miltefosine treatment. Other gastrointestinal, musculoskeletal, and total adverse events were not statistically different in the two groups during one to four weeks after therapy initiation. No relevant changes were observed in levels of liver enzymes, creatinine and hematological tests before and after end of treatment in both groups. In conclusion, miltefosine is apparently at least as good as meglumine antimoniate for the treatment of cutaneous leishmaniasis caused by
L. major in Iran, based on parasitological as well as clinical criteria two weeks, three months, and six months after end of treatment.
The aim of present study was to determine the seroprevalence of canine visceral leishmaniasis (CVL) among stray and owned dogs in Kouhsar district of Alborz Province, central Iran.
The study was ...performed from March 2011 to July 2011 using Direct Agglutination Test (DAT). Three hundred and thirty seven dogs including 257 stary and 80 owned dogs were selected by random sampling. The agreement between serological data and sex, age, life style of dogs and clinical signs were assessed by Chi-square.
DAT showed that from 337 serum samples collected from owned and stray dogs, 12sera (3.6%) were positive. The seroprevalance was 10% (8/80) among owned dogs and 1.6% (4/257) among stray dogs. A significant difference in seroplevalance was seen between owned and stray dogs (P = 0.01). The highest seroprevalence rate (14%) was observed among the ownership dogs of 5 years old and above. Statistical analysis revealed significant relation between seroprelvalence and age (P= 0.02). There was no statistically significant relation between male (6.3%) and female (2.2%) seroprevalence (P= 0.085).
This survey indicates the importance and necessity of serologic screening of visceral leishmaniasis in human and dogs in Kouhsar district.
Over the last decade, a few cases of visceral leishmaniasis (VL) have been reported in some districts of the province of Golestan, in north-eastern Iran. The aim of the present study was to ...investigate the prevalence of Leishmania infantum infection among humans and domestic dogs by using direct agglutination test (DAT) and PCR assays in the eastern zone of the province. Between 2011 and 2012, blood samples were randomly collected from 450 humans and 50 domestic dogs, in the eastern zone of Golestan Province including 7 villages from Marave-tappeh district where new cases of human VL had been recorded there. Each of these samples was tested for anti-Leishmania antibodies, in DAT, and for L. infantum kinetoplast DNA on whole blood, in PCR-based assays. A total of 450 human samples, 6 (1.33 %) were found seropositive and 13 (2.8 %) was found PCR-positive. Of the 50 dog samples, 16 (32 %) were found seropositive and 15 (30 %) were PCR-positive. All PCR-positive dogs were found seropositive except one as well as 6 (46.2 %) PCR-positive humans were also found seropositive. Moreover, the species of L. infantum was detected in all PCR–positive samples. The high prevalence of VL in the study areas offer it has emerged as an endemic focus in the province. Further investigations on the vectors, reservoirs and human population are recommended.
Toxoplasma gondii
is an obligate intracellular protozoan parasite that infects humans and animals.
T. gondii
surface antigen 1 (SAG1) is an appropriate antigen with high specificity and sensitivity ...for the detection of
T. gondii
infection in humans and animal hosts. The aim of this study was to determine the seroprevalence of
T. gondii
infection using SAG1 antigen (P30) in ownership dogs in Meshkin-Shahr district in the northwestern Iran. The sera samples were collected from 171 domestic dogs and tested using indirect ELISA (SAG1 antigen). The data were analyzed using SPSS software version 13. From a total of 171 dogs, 82 (48 %) of them were sero-positive. No statistical significant difference was seen between
T. gondii
infection and gender (
P
= 0.995). The highest sero-prevalence of rate was observed in >5 years animals; but no statistical significant difference was seen between
T. gondii
infection and age (
P
= 0.589). Our findings indicate that
Toxoplasma
seropositivity rate is high in ownership dogs in northwest of Iran. This is probably due to high exposure to contaminated food, soil, or water sources with sporulated
Toxoplasma
oocysts.
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