One-Step Synthesis of a Non-Precious-Metal Tris (Fe/N/F)-Doped Carbon Catalyst for Oxygen Reduction Reactions.

Advancements in inexpensive, efficient, and durable oxygen reduction catalysts is important for maintaining the sustainable development of fuel cells. Although doping carbon materials with transition metals or heteroatomic doping is inexpensive and enhances the electrocatalytic performance of the catalyst, because the charge distribution on its surface is adjusted, the development of a simple method for the synthesis of doped carbon materials remains challenging. Here, a non-precious-metal tris (Fe/N/F)-doped particulate porous carbon material (21P2-Fe1-850) was synthesized by employing a one-step process, using 2-methylimidazole, polytetrafluoroethylene, and FeCl3 as raw materials. The synthesized catalyst exhibited a good oxygen reduction reaction performance with a half-wave potential of 0.85 V in an alkaline medium (compared with 0.84 V of commercial Pt/C). Moreover, it had better stability and methanol resistance than Pt/C. This was mainly attributed to the effect of the tris (Fe/N/F)-doped carbon material on the morphology and chemical composition of the catalyst, thereby enhancing the catalyst's oxygen reduction reaction properties. This work provides a versatile method for the gentle and rapid synthesis of highly electronegative heteroatoms and transition metal co-doped carbon materials.

Prevalence of HIV and malaria: a cross-sectional study on Bioko Island, Equatorial Guinea.

Malaria and HIV are two of the most severe public health problems in Africa. However, epidemiological data on Bioko Island is scarce. To investigate the prevalence of malaria and HIV infections and assess association of malaria and HIV infections and possible confounding factors, we performed a cross-sectional survey of people of malaria-endemic Bioko Island, Equatorial Guinea. A cross-sectional study of 1 526 subjects was carried out to determine the prevalence of malaria and HIV infection in Malabo region hospital on Bioko Island. Questionnaires were administered and venous blood samples were drawn for malaria parasites and HIV detection. The prevalence of participants infected with malaria and HIV in this area were 13.8% and 6.6% respectively. The average prevalence of co-infection for malaria and HIV was 0.92%. HIV-infection was significantly associated with the age and gender. Malaria infections were significantly associated with the age. This study showed that the prevalence of HIV and malaria on Bioko Island was higher than expected, although the co-infection prevalence of malaria and HIV was low. The results also indicated that malaria and HIV infections lead to more public health risk to youngsters and women.

Limited artemisinin resistance-associated polymorphisms in Plasmodium falciparum K13-propeller and PfATPase6 gene isolated from Bioko Island, Equatorial Guinea.

OBJECTIVE: With emergence and geographically expanding of antimalarial resistance worldwide, molecular markers are essential tool for surveillance of resistant Plasmodium parasites. Recently, single-nucleotide polymorphisms (SNPs) in the PF3D7_1343700 kelch propeller (K13-propeller) domain are shown to be associated with artemisinin (ART) resistance in vivo and in vitro. This study aims to investigate the ART resistance-associated polymorphisms of K13-propeller and PfATPase6 genes in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea (EG). METHODS: A total of 172 samples were collected from falciparum malaria patients on Bioko Island between 2013 and 2014. The polymorphisms of K13-propeller and PfATPase6 genes were analyzed by Nest-PCR and sequencing. RESULTS: Sequences of K13-propeller and PfATPase6 were obtained from 90.74% (98/108) and 91.45% (139/152) samples, respectively. The 2.04% (2/98) cases had non-synonymous K13-propeller A578S mutation but no found the mutations associated with ART resistance in Southeast Asia. For PfATPase6, the mutations were found at positions N569K and A630S with the mutation prevalence of 7.91% (11/139) and 1.44% (2/139), respectively. In addition, a sample with the mixed type at position I723V was discovered (0.72%, 1/139). CONCLUSIONS: This study initially offers an insight of K13-propeller and PfATPase6 polymorphisms on Bioko Island, EG. It suggests no widespread ART resistance or tolerance in the region, and might be helpful for developing and updating guidance for the use of ART-based combination therapies (ACTs).

Molecular Epidemiological Characterization and Health Burden of Thalassemias in the Chaoshan Region, People's Republic of China.

Thalassemia is one of the most prevalent inherited disease in southern China. However, there have been only a few epidemiological studies of thalassemia in the Chaoshan region of Guangdong Province, People's Republic of China (PRC). A total of 6231 unrelated subjects in two main geographical cities of the Chaoshan region was analyzed for thalassemia. Seven hundred and thirty-six cases of suspected thalassemia carriers with microcytosis [mean corpuscular volume (MCV) <82.0 fL] were found by complete blood cell (CBC) count, and were tested by reverse dot-blot gene chip to reveal a total of 331 mutant chromosomes, including 278 α-thalassemia (α-thal) alleles and 53 ß-thalassemia (ß-thal) alleles. The most common α-thal mutations were the Southeast Asian (- -(SEA)), followed by the -α(3.7) (rightward) and -α(4.2) (leftward) deletions. The two most common ß-thal mutations were HBB: c.316-197C>T and HBB: c.126_129delCTTT, accounting for 69.81% of the ß-thal defects in the studied individuals. In addition, a rare mutation, Cap +1 (A>C) (HBB: c.-50A>C) was described for the first time in the Chaoshan region. Our results gave a heterozygote frequency of 5.31% for common α- and ß-thal in the Chaoshan region, and also indicated a higher prevalence of thalassemia with a heterozygote frequency of 6.29% in Chaozhou, followed by Shantou (3.37%). This study provided a detailed prevalence and molecular characterization of thalassemia in the Chaoshan region, and will be valuable for developing a strategy for prevention of thalassemia and reducing excessive health care costs in this area.

Seroprevalence of Human Immunodeficiency Virus, Hepatitis B Virus, Hepatitis C Virus, and Treponema pallidum Infections among Blood Donors on Bioko Island, Equatorial Guinea.

BACKGROUND: Regular screening of transfusion-transmissible infections (TTIs), such as human immunodeficiency virus (HIV), hepatitis B and hepatitis C virus (HBV and HCV, respectively), and Treponema pallidum, in blood donors is essential to guaranteeing clinical transfusion safety. This study aimed to determine the seroprevalence of four TTIs among blood donors on Bioko Island, Equatorial Guinea (EG). METHODS: A retrospective survey of blood donors from January 2011 to April 2013 was conducted to assess the presence of HIV, HBV, HCV and T. pallidum. The medical records were analyzed to verify the seroprevalence of these TTIs among blood donations stratified by gender, age and geographical region. RESULTS: Of the total 2937 consecutive blood donors, 1098 (37.39%) had a minimum of one TTI and 185 (6.29%) harbored co-infections. The general seroprevalence of HIV, HBV, HCV and T. pallidum were 7.83%, 10.01%, 3.71% and 21.51%, respectively. The most frequent TTI co-infections were HBV-T. pallidum 60 (2.04%) and HIV-T. pallidum 46 (1.57%). The seroprevalence of HIV, HBV, HCV and T. pallidum were highest among blood donors 38 to 47 years, 18 to 27 years and ≥ 48 years age, respectively (P<0.05). The seroprevalence of TTIs varied according to the population from which the blood was collected on Bioko Island. CONCLUSIONS: Our results firstly provide a comprehensive overview of TTIs among blood donors on Bioko Island. Strict screening of blood donors and improved hematological examinations using standard operating procedures are recommended.

Molecular mutation profile of Pfcrt and Pfmdr1 in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea.

BACKGROUND: Antimalarial drug resistance is a primary public health problem. Haplotypes of pfcrt and pfmdr1 gene have been implicated to be molecular markers of chloroquine (CQ) resistance. This study aims to explore mutation distribution of Pfcrt and Pfmdr1 in Bioko Island, Equatorial Guinea (EG). METHODS: Blood samples were collected from different districts of Bioko. The single nucleotide polymorphisms in Pfcrt (codons 72 to 76) and Pfmdr1 (codons 86, 130, 184, 1034, 1042, 1109 and 1246) were assessed by nested PCR with DNA sequencing and haplotype prevalences were also determined. RESULTS: Analysis of Pfcrt and Pfmdr1 mutations was successful in 151 and 157 samples respectively out of the 172 samples taken for this study. The mutations of Pfcrt and Pfmdr1 were found in 98.67% and 89.81% isolates, respectively. The Pfcrt 74-76, Pfmdr1 86, and Pfmdr1 184 were 92.05%, 50.32%, and 87.26% found mostly of mutation type, respectively. Three haplotypes coding 72-76 of Pfcrt were found including CVMNK, CVIET, and CVM/I N/E K/T, which accounted for 1.33%, 92.05%, and 6.62%, respectively. No mutation in Pfmdr1-N1 codon at 130 and Pfmdr1-N2 (S1034C, N1042D, V1109I, and D1246Y) was detected. The types coding 86 and 184 in Pfmdr1 were found including NY, YY, NF, YF, NY/F and YY/F, which accounted for 10.19%, 2.55%, 33.76%, 45.22%, 5.73% and 2.55%, respectively. CONCLUSION: High prevalence of Pfcrt CVIET and Pfmdr1 86Y, 184F double mutations confirm high-level CQ resistance (CQR) and might suggest reduced susceptibility of Plasmodium falciparum isolates to AQ in Bioko, EG. It establishes fundamental data for detection of P. falciparum CQR with molecular markers and will promotes the surveillance level of drug resistance in Bioko, EG.

Molecular Epidemiological Investigation of Thalassemia in the Chengdu Region, Sichuan Province, Southwest China.

Thalassemia is the most common inherited disease in southern China. However, this disorder is usually ignored by the health system in the Sichuan Province due to the lack of epidemiological data. To provide basic epidemiological data for thalassemia screening, genetic counseling, and prenatal diagnosis (PND) in the Chengdu region, a total of 3262 healthy subjects were assessed by complete blood count (CBC), reverse dot-blot gene chip, gap-polymerase chain reaction (gap-PCR), and PCR-DNA sequencing. A frequency of heterozygous thalassemia of 3.43% (112/3262) was found, of which 2.21% (72/3262) patients carried α-thalassemia (α-thal), 1.19% (39/3262) ß-thalassemia (ß-thal) and 0.3% (1/3262) hereditary persistence of fetal hemoglobin (Hb) (HPFH)/δß-thalassemia (δß-thal). Four types of α-thal mutations were found, the most prevalent being - -(SEA) (68.06%), followed by -α(3.7) (rightward deletion, 25.0%), Hb Quong Sze (Hb QS; HBA2: c.377 T > C) (4.17%), and -α(4.2) (leftward deletion, 2.78%). The seven ß-thal mutations included: codons 41/42 (-TTCT), HBB: c.126_129delCTTT (13/39, 33.33%); codon 17 (A > T), HBB: c.52 A > T (11/39, 28.95%); IVS-II-654 (C > T), HBB: c.316-197 C > T (9/39, 23.68%); -28 (A > G), HBB: c.-78 A > G (3/39, 7.69%); -29 (A > G), HBB: c.-79 A > G (1/39, 2.56%); codons 27/28 (+C), HBB: c.84_85insC (1/39, 2.56%), and the rare IVS-II-850 (G > T), HBB: c.316-1 G > T (1/39, 2.56%). Only one case of the Southeast Asian HPFH deletion was found. This is the first detailed molecular epidemiological survey of thalassemia in the Chengdu region, Sichuan Province, People's Republic of China (PRC).

High prevalence of pfmdr1 N86Y and Y184F mutations in Plasmodium falciparum isolates from Bioko Island, Equatorial Guinea.

OBJECTIVE: Drug resistance against Plasmodium falciparum has been recognized as the crucial obstacle to curbing mortality and morbidity from malaria. To investigate the distribution and pattern of multidrug resistance 1 (pfmdr1) gene polymorphisms in P. falciparum, isolates collected from the malaria high-endemic Bioko Island, Equatorial Guinea. METHODS: Blood samples were collected from 217 patients with P. falciparum malaria during rainy season in 2012 on Bioko Island. These samples were extracted using Chelex to obtain parasite DNA. Nest-polymerase chain reaction (PCR) and sequencing were employed to detect mutations (N86Y, E130K, Y184F, S1034C, N1042D, V1109I, and D1246Y) and haplotypes in pfmdr1 gene. RESULTS: A total of 151 samples were successfully detected for pfmdr1 mutations from the 217 patients. Pfmdr1 mutations were found in 91·39% (138/151) P. falciparum isolates. However, no mutation at 130 and 1109 was identified from these samples. Four haplotypes coding 86, 184, 1034, 1,042, and 1,246 were found including NYSND, YYSND, NFSND, and YFSND, which accounted for 8·61% (13/151), 2·65% (4/151), 29·80% (45/151), and 58·94% (89/151), respectively. CONCLUSIONS: Our results exhibited hypersensitivity to lumefantrine (LU) and mefloquine (MQ) and resistance to chloroquine (CQ) and amodiaquine (AQ) in P. falciparum isolates from Bioko Island. This information will be useful for anti-malarial drug policy in Equatorial Guinea.

High resolution melting analysis: a rapid screening and typing tool for common ß-thalassemia mutation in Chinese population.

ß-thalassemia is a common inherited disorder worldwide including southern China, and at least 45 distinct ß-thalassemia mutations have been identified in China. High-resolution melting (HRM) assay was recently introduced as a rapid, inexpensive and effective method for genotyping. However, there was no systemic study on the diagnostic capability of HRM to identify ß-thalassemia. Here, we used an improved HRM method to screen and type 12 common ß-thalassemia mutations in Chinese, and the rapidity and reliability of this method was investigated. The whole PCR and HRM procedure could be completed in 40 min. The heterozygous mutations and 4 kinds of homozygous mutations could be readily differentiated from the melting curve except c.-78A>G heterozygote and c.-79A>G heterozygote. The diagnostic reliability of this HRM assay was evaluated on 756 pre-typed genomic DNA samples and 50 cases of blood spots on filter paper, which were collected from seven high prevalent provinces in southern China. If c.-78A>G heterozygote and c.-79A>G heterozygote were classified into the same group (c.-78&79 A>G heterozygote), the HRM method was in complete concordance with the reference method (reverse dot blot/DNA-sequencing). In a conclusion, the HRM method appears to be an accurate and sensitive method for the rapid screening and identification of ß-thalassemia mutations. In the future, we suggest this technology to be used in neonatal blood spot screening program. It could enlarge the coverage of ß-thalassemia screening program in China. At the same time, its value should be confirmed in prospectively clinical and epidemiological studies.

Molecular epidemiological characterization and health burden of thalassemia in Jiangxi Province, P. R. China.

BACKGROUND: Thalassemia is the most common inherited disease in southern China. However, this disorder is usually ignored by Jiangxi provincial health system and government due to lack of epidemiological data. MATERIALS AND METHODS: A total of 9489 samples from Hakka Han and Gan-speaking Han in three geographical areas of Jiangxi Province were analyzed for both complete blood cell (CBC) count and reverse dot blot (RDB) gene chip for thalassemia. RESULTS: 1182 cases of suspected thalassemia carriers with microcytosis (MCV<82 fL) were found by CBC count, and were tested by RDB gene chip to reveal a total of 594 mutant chromosomes, including 433 α-thalassemia mutant chromosomes and 172 ß-thalassemia mutant chromosomes. Our results indicated a higher prevalence of thalassemia with the heterozygote frequency of 9.49% in southern Jiangxi province, whereas the low frequency was found in middle (3.90%) and northern Jiangxi (2.63%). CONCLUSIONS: Based on the epidemiological data, the estimated numbers of pregnancies in Jiangxi province in which the fetus is at risk for ß-thalassemia major or intermedia, Bart's hydrops fetalis and Hb H disease are 34 (95% CI, 16 to 58), 79 (95% CI, 50 to 114) and 39 (95% CI, 27 to 58) per year, respectively. We suggested that prevention network of thalassemia should be established, especially in high prevalent southern Jiangxi (Hakka Han), including establishment of thalassemia database collection, hematological analysis laboratories, genetic counselling clinics, prenatal diagnosis centers and neonatal screening centers.

Rapid screening for sickle cell disease by polymerase chain reaction-high resolution melting analysis.

Each year, ~300,000 individuals with sickle cell disease (SCD), a hemoglobinopathy caused by ß-globin gene mutation, are born, and >75% of those are in Africa. The present study examined 511 individuals on the island of Bioko (Equatorial Guinea) and attempted to establish a method for rapid sickle cell disease screening. Following DNA extraction and polymerase chain reaction (PCR) amplification, high resolution melting (HRM) analysis was used to assess the specificity of fluorescence signals of the PCR products and to differentiate various genotypes of these products. The analytical results of HRM were validated using DNA sequencing. By HRM analysis, 80 out of 511 samples were classified as hemoglobin S (Hb S) heterozygotes, while 431 out of 511 samples were classified as wild-type. No mutant homozygote was identified. DNA sequencing indicated that within the 431 wild-type samples as indicated by HRM analysis, one case was actually a Hb S heterozygote and another case was a rare hemoglobin S-C genotype (sickle-hemoglobin C disease). One out of 80 suspected Hb S heterozygotes as indicated by HRM was confirmed as wild-type by DNA sequencing and the results of residual 508 cases were consistent for HRM analysis and sequencing. In conclusion, HRM analysis is a simple, high-efficiency approach for Hb S screening and is useful for early diagnosis of SCD and particularly suitable for application in the African area.

Hemoglobinopathy: molecular epidemiological characteristics and health effects on Hakka people in the Meizhou region, southern China.

BACKGROUND: Hemoglobinopathies are the most common inherited diseases in southern China. However, there have been only a few epidemiological studies of hemoglobinopathies in Guangdong province. MATERIALS AND METHODS: Peripheral blood samples were collected from 15299 "healthy" unrelated subjects of dominantly ethnic Hakka in the Meizhou region, on which hemoglobin electrophoresis and routine blood tests were performed. Suspected cases with hemoglobin variants and hereditary persistence of fetal hemoglobin (HPFH) were further characterized by PCR, DNA sequencing, reverse dot blot (RDB) or multiplex ligation-dependent probe amplification (MLPA). In addition, 1743 samples were randomly selected from the 15299 subjects for thalassemia screening, and suspected thalassemia carriers were identified by PCR and RDB. RESULTS: The gene frequency of hemoglobin variants was 0.477% (73/15299). The five main subgroups of the ten hemoglobin variants were Hb E, Hb G-Chinese, Hb Q-Tahiland, Hb New York and Hb J-Bangkok. 277 cases (15.89%, 277/1743) of suspected thalassemia carriers with microcytosis (MCV<82 fl) were found by thalassemia screening, and were tested by a RDB gene chip to reveal a total of 196 mutant chromosomes: including 124 α-thalassemia mutant chromosomes and 72 ß-thalassemia mutant chromosomes. These results give a heterozygote frequency of 11.24% for common α and ß thalassemia in the Hakka population in the Meizhou region. 3 cases of HPFH/δß-thalassemia were found, including 2 cases of Vietnamese HPFH (FPFH-7) and a rare Belgian( G)γ((A)γδß)°-thalassemia identified in Chinese. CONCLUSIONS: Our results provide a detailed prevalence and molecular characterization of hemoglobinopathies in Hakka people of the Meizhou region. The estimated numbers of pregnancies each year in the Meizhou region, in which the fetus would be at risk for ß thalassemia major or intermedia, Bart's hydrops fetalis, and Hb H disease, are 25 (95% CI, 15 to 38), 40 (95% CI, 26 to 57), and 15 (95% CI, 8 to 23), respectively.