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A 60-day feeding experiment was performed to evaluate the effect of dietary astaxanthin on gonad development, the antioxidant system, and its inherent mechanism in female Nile tilapia (Oreochromis niloticus). Fish were fed with diets containing astaxanthin at five levels [0 mg/kg (control), 50 mg/kg, 100 mg/kg, 150 mg/kg, and 200 mg/kg]. At the end of experiment, the group fed with 150 mg/kg astaxanthin showed significantly increased specific growth rate, feed utilization, viscerosomatic index, and hepatosomatic index compared with the control group ( P < 0.05 ). Gonad development was stimulated in the groups fed with 100 mg/kg and 150 mg/kg astaxanthin, and their gonadosomatic index and egg diameter were significantly higher than those of the control group and the group fed with 200 mg/kg astaxanthin. The ovaries of females in the groups fed with 100 mg/kg and 150 mg/kg astaxanthin were fully developed, the eggs were gray-yellow and uniform in size, and a large number of oocytes developed to stages IV and V. The serum levels of 17 β-estradiol, follicle-stimulating hormone, and luteinizing hormone were significantly higher in the groups fed with 100 mg/kg and 150 mg/kg astaxanthin than in the group fed with 200 mg/kg astaxanthin. Compared with the control and the other groups, the group fed with 150 mg/kg astaxanthin showed significantly higher transcript levels of genes encoding hormone receptors and higher catalase activity in ovarian tissues, lower malondialdehyde content, decreased apoptosis (reduced granulosa cell apoptosis and lower transcript levels of bax and caspase-3), and reduced follicular atresia. Gene ontology analyses revealed that cell division and the cell cycle were enriched with differentially expressed genes in the group fed with 150 mg/kg astaxanthin, compared with the control group. We concluded that dietary astaxanthin at a concentration of 150 mg/kg activates follicle development by inhibiting expression of mapk1 (involved in MAPK signaling) and increasing the expression genes involved in oocyte meiosis (chp2, ppp3ca, map2k1, and smc1a1) and progesterone-mediated oocyte maturation (igf1, plk1, and cdk1). In conclusion, female Nile tilapia fed with 150 mg/kg astaxanthin showed increased growth, reduced oxidative stress in ovarian tissue, lower levels of cell apoptosis, and improved oocyte development.

The mechanism of Pd-catalyzed desymmetric monoarylation of dihydrosilanes with aryl iodides in the presence of chiral TADDOL-derived phosphoramidite ligand toward deeper understanding of the stereoselectivity has been investigated using hybrid density functional theory (DFT) methodology. The full catalytic cycle for the favorable reaction pathway, which is initiated by the oxidative addition of aryl iodide to monoligated Pd0 leading to the silylation product, was calculated. The DFT calculation results indicate that the enantio-discriminating transmetalation between Pd-Ar bond of the Pd(II) aryl iodide complex and Si-H bond of the prochiral dihydrosilane was the enantioselectivity-determining step. On the basis of the structure of the transition state, the attractive aryl-aryl interactions between the aryl group of ligand, aryl iodide, and dihydrosilane were found to play an important role for the chiral transference from the chiral ligand to asymmetric cleavage of the Si-H bond of the prochiral dihydrosilane.

The increasing demand for high-energy Li-ion batteries (LIBs) continues to push the development of electrode materials, particularly cathode materials, towards their capacity limits. Despite the enormous success, the stability and reliability of LIBs are becoming a serious concern due to the much-aggravated side reactions between electrode materials and organic electrolytes. How to stabilize the cathode/electrolyte interface is therefore an imperative and urgent task drawing considerable attention from both academia and industry. An active treatment on the surface of cathode materials, usually by introducing an inert protection layer, to diminish their side reaction with electrolytes turns out to be a reasonable and effective strategy. This Feature Article firstly outlines our synthesis efforts for the construction of a uniform surface nanocoating on various cathode materials. Different wet chemical routes have been designed to facilitate the control of growth kinetics of targeted coating species so that a precise surface coating could be achieved with nanometer accuracy. Furthermore, we showed the possibility to transform the outer coating layer into a surface doping effect through surface solid reaction at high temperature. A detailed discussion on the structure-performance relationship of these surface-controlled cathode materials is introduced to probe the stabilization mechanism. Finally, perspectives on the development tendency of high-energy cathodes for stable LIBs are provided.

Since the first perovskite CaTiO3 was discovered in 1839, the development of perovskite has a history of 180 years. The emergence of solar cells (CH3 NH3 )PbI3 has set off the trend of hybrid organic-inorganic perovskite (HOIP) materials. Since then, various HOIPs have sprung up and been widely used in various material devices. Among them, HOIP ferroelectrics have gained widespread attention. However, antiperovskite, as a twin brother of perovskite, has been neglected although it has similar structure with perovskite. Here, we successfully found that [C3 H7 FN]3 [SnCl6 ]Cl has a three-dimensional (3D) antiperovskite structure with the formula M3 AB. Importantly, the compound exhibits obvious ferroelectric properties with an Aizu notation of 622F6 at 391 K. To the best of our knowledge, this is the first 3D hybrid organic-inorganic antiperovskite ferroelectric, which will greatly promote the development of antiperovskite families with more superior physical properties.

Two-dimensional (2D) organic-inorganic perovskites (OIPs), with improved material stability over their 3D counterparts, are highly desirable for device applications. It is their considerable structural diversity that offers an unprecedented opportunity to engineer materials with fine-tuning functionalities. The isosteric substitution of hydrogen by an electronegative fluorine atom has been proposed as a useful route to improve the photovoltaic performance of 2D OIPs, whereas its valuable role in developing ferroelectricity is still waiting for further exploration. Herein, for the first time we applied fluorinated aromatic cations in extending the family of 2D OIP ferroelectrics, and successfully obtained [2-fluorobenzylammonium]2PbCl4 as a high-performance ferroelectric semiconductor. The failures in the nonferroelectric [4-fluorobenzylammonium]2PbCl4 and [3-fluorobenzylammonium]2PbCl4 demonstrate that the selective introduction of fluorine in correct structural positions is particularly essential. This work represents an unprecedented proof-of-concept in the use of fluorinated aromatic cations for the targeted design of excellent 2D OIP ferroelectrics, and is believed to inspire the future development of low-cost, high-efficiency, and stable device applications.

The aim of the research was to evaluate the efficacy and safety associated with Shexiang Tongxin Dropping Pills combined with conventional therapy for patients with coronary heart disease(CHD). We searched 8 electronic databases up to November 2020, including PubMed, Cochrane Library, EMbase, Web of Science, CNKI, Wanfang, VIP and SinoMed. Eligible studies were clinical trials of Shexiang Tongxin Dropping Pills combined with conventional therapy used in the treatment of coronary heart disease(CHD). The Meta-analysis was performed using STATA 15 software. A total of 21 RCTs(n=2 186) were shortlisted for the Meta-analysis. The results of efficacy evaluation showed that the total effective rate of Shexiang Tongxin Dropping Pills combined with conventional therapy was higher than that of conventional therapy of coronary heart disease(RR=1.20, 95%CI[1.15, 1.26], Z=8.63, Plt;0.001). Furthermore, Shexiang Tongxin Dripping Pills combined with conventional therapy had better effect on electrocardiogram efficacy(RR=1.24, 95%CI[1.16, 1.34], Z=5.98, Plt;0.001) and the number of angina attacks(SMD=-2.30, 95%CI[-3.47,-1.14], Z=3.88, Plt;0.001), the duration of angina attack(SMD=-2.31, 95%CI[-3.07,-1.55], Z=5.97, Plt;0.001), with lower levels of LDL-C(SMD=-0.73, 95%CI[-1.32,-0.14], Z=2.42, P=0.016), TC(SMD=-1.16, 95%CI[-1.35,-0.96], Z=11.56, Plt;0.001) and TG(SMD=-0.87, 95%CI[-1.06,-0.68], Z=8.97, Plt;0.001), and higher levels of HDL-C(SMD=0.87, 95%CI[0.02, 1.71], Z=2.00, P=0.045). The results of safety evaluation showed that the incidence of adverse reactions of Shexiang Tongxin Dropping Pills combined with conventional therapy was lower than that of conventional therapy of coronary heart disease(RR=0.45, 95%CI[0.22, 0.91], Z=2.23, P=0.026). There were significant differences in the above outcome indexes between the two groups. After the Harbord method test, the total effective rate outcome index has publication bias, but the sensitivity analysis of the cut-and-fill method suggested that the result was stable. In general, limited by the quantity and quality of included literature, more high-quality studies are needed to further verify the conclusions of this study.

This research was to evaluate the economics of Shexiang Tongxin Dropping Pills combined with conventional therapy for patients with coronary heart disease(CHD) in Chinese medical environment. From the perspective of medical insurance, a Markov model was established in this study based on the results of Meta-analysis comparing the effectiveness and safety of Shexiang Tongxin Dripping Pills combined with conventional treatment and conventional treatment alone. The experimental group was treated with She-xiang Tongxin Dropping Pills combined with conventional Western medicine treatment, while the control group was treated with conventional Western medicine treatment alone. The cost-utility analysis and sensitivity analysis were performed for the two regimens using Treeage pro. After 30 cycles of model simulation, according to the results of Markov model, the total cost and health output were CNY 237 795.73 and 16.36 QALYs(the quality adjusted life years, QALYs), respectively for Shexiang Tongxin Dropping Pills combined with conventional Western medicine treatment, CNY 247 396.55 and 16.36 QALYs respectively for the conventional Western medicine treatment alone. Compared with the conventional treatment alone, the Shexiang Tongxin Dropping Pills combined with conventional treatment had lower long-term cost and higher health output, with advantages of cost-utility and pharmacoeconomic advantages. The sensitivity analysis results showed that the conclusion was relatively stable. Based on the above results, it is considered that compared with the conventional Western medicine alone, Shexiang Tongxin Dropping Pill combined with conventional Western medicine is a treatment regimen with pharmacoeconomic advantages for the treatment of CHD.

Pollutant-attached microplastics have received increasing attention in recent years. However, information regarding the influence of hydroxyl group content of pollutants on the adsorption and desorption behavior is unclear, which affects their fate and risks in the aquatic environment. In this study, we investigated the adsorption and desorption behavior of anthracene (ANT) and its hydroxy derivatives (OHAs), including 2-hydroxyanthracene (MOHA), 2,6-dihydroxyanthracene (DOHA), and 1,8,9-trihydroxyanthracene (TOHA) on polyvinyl chloride (PVC) microplastics, and their interaction mechanism through the batch, characterization, and computational experiments. The results showed that the adsorption of ANT and OHAs on PVC microplastics conformed to the pseudo-second-order kinetic model and was exothermic spontaneously. The adsorption efficiency on PVC followed the order of ANT > MOHA > DOHA > TOHA, indicating that increase in hydroxyl group substitution degree will inhibit pollutant adsorption on PVC microplastics. Conversely, the release amounts of MOHA from PVC into simulated gastric fluids were higher than those of ANT. Experimental and computational results suggested that the affinity of ANT/OHAs to PVC microplastics was the most likely outcome in hydrophobic effect, electrostatic repulsion, and CH-π interaction forces. These findings help elucidate the mechanisms of pollutant adsorption on microplastics and evaluate the risk of pollutant-attached microplastics in the aquatic environment.

It is unclear what role does obesity (OB) index play between blood lipid and bone mineral density (BMD).This study recruited a total of 4,558 Chinese elders65 years. OB indices: waist circumference (WC), body mass index (BMI), waist-hip-ratio (WHR); blood lipid parameters: low density lipoprotein (LDL); total cholesterol (TC), triglyceride (TG), and BMDs at femur neck (FN), total hip (TH), and lumbar spine (LS) were measured. The t-test and multiple linear regression analysis were used to detect the differences of variables. Casual inference test (CIT) were performed to test potential mediators underlying the associations between blood lipid and BMD.The blood lipids were positively associated with BMD (p 0.05) after adjustment of age and sex (Model 1) both in total subjects and in sex-stratified subjects. The CIT showed that OB indices had significant mediation effects on the associations between blood lipid (TG and LDL) and BMD in total subjects and males. Comparably, the correlations of TG and BMD are most likely mediated by BMI and WC.This study represented the first effort to report that OB indices, especially BMI and WC, served as significant mediators between blood lipid (TG and LDL) and BMD in Chinese elderly.

The significant Tc enhancement of 110 K in [N-fluoromethyldabconium] triiodide lead caused by the promising design of H/F substitution is the first and unprecedented, opening up an applicable and universal strategy to effectively regulate the Tc working temperature in phase transition materials.

The conventional and newly developed geometry parameters at the femoral neck have formed a large geometry profile and their relationship with hip fracture was largely unknown. We aimed to evaluate the relationship between the geometry profile and hip fracture in Chinese.The hip geometry profile contains seven conventional geometry parameters at femoral neck (FN) and thirty newly developed parameters at three sub-regions (Narrow Neck, NN; Intertrochanter, IT; Femoral shaft, FS) of the total hip. Based on 6294 recruited Chinese (≥65 years), 97 subjects with osteoporotic fracture (OF) history and 388 matched controls were selected. The t test, Chi-square statistic, conditional logistic regression model were used.Three geometric parameters (endocortical diameter, ED; cortical thickness, CT; buckling ratio, BR) have consistent differences at all the sites between the cases and controls (p 0.01). Conventional geometry parameters (e.g., cross-sectional area, CSA; BR) and the newly developed parameters (e.g., NN_ED, NN_Outer Diameter, IT_ED) were identified as the risk factors of hip fracture independent of BMD. The additional predictive ability of the hip geometric parameters, over BMD alone, (receiver operating characteristic curve (ROC) analysis) was improved. Especially at NN, the area of ROC used single NN_BMD is only 0.596, but increased rapidly at 0.705 when combined with the hip geometric parameters.This study found that three newly developed hip geometry parameters are associated with hip fracture. The results will increase our understanding of the determinants of fracture and provide potential clue for future prevention of fracture in Chinese Population.

A highly chemoselective platinum-catalyzed mono-lateral diboration of dialkynylsilanes for the construction of silicon-tethered alkynyl diborylalkenes is described, in which tris(4-methoxyphenyl)phosphine was found to be an effective ligand for the cis-addition of diboron agents to the silicon-tethered alkynes, and the chiral ligand (AFSi-Phos)-mediated diboration of dialkynylsilanes resulted in the desymmetric construction of silicon-stereogenic centers with promising enantioselectivity.

Irisin, a myokine produced by skeletal muscle in response to physical exercise, promotes trans-differentiation of white adipose tissue into brown adipose tissue. Recent evidences suggested that irisin also plays an important role in the control of bone metabolism. This study aimed to ascertain the relationship between plasma irisin and bone mineral density (BMD) in Chinese population by adoption of an extreme sampling method. Based on a large and screened Chinese elderly population (N = 6308), two subgroups with extremely high and low hip BMD were selected for discovery (N = 80, high vs. low BMD = 44:36) and validation (N = 60, high vs. low BMD = 30:30), respectively. Plasma irisin, P1NP, and β-CTx were measured using commercially available ELISA kits. Other metabolic parameters (e.g., blood glucose, total cholesterol and triglycerides) were collected. Student's t test and Spearman correlation analyses were conducted in SPSS. Significant difference was discovered for plasma irisin between females and age-matched males (N = 80, male vs. female = 42:38, P = 0.002). The plasma irisin levels were significantly higher in high BMD subjects than in low BMD subjects, which was observed in both discovery (P = 0.012) and validation samples (P = 0.022). However, such observation was limited to males only. Further correlation analyses in males showed that plasma irisin was correlated with BMD (r = 0.362, P = 0.025) and triglyceride (r = - 0.354, P = 0.032). Plasma irisin levels were associated with hip BMD in Chinese elderly men. This study represented the first effort of investigating the relationship of plasma irisin and BMD in elderly population. The positive correlation between plasma irisin and BMD hints intrinsic communication between muscle and bone.

A host-guest inclusion compound, 18-crown-6 oxonium tetrachloride-gallium(iii), was shown to undergo a 4/mmmFmm2-type ferroelectric phase transition with four crystallographically equivalent polarization directions at 337 K. To the best of our knowledge, this is the first host-guest inclusion compound shown to be a high-temperature multiaxial molecular ferroelectric.

Since the first perovskite CaTiO

The significant Tc enhancement of 110 K in [N-fluoromethyldabconium] triiodide lead caused by the promising design of H/F substitution is the first and unprecedented, opening up an applicable and universal strategy to effectively regulate the Tc working temperature in phase transition materials.

To identify the dominant epitopes of α-8 giardin in Giardia lamblia, and analyze their immunoreactivity.Three dominant epitopes G1（7-17 aa）, G2（30-40 aa） and G3（296-306 aa） were predicted for α-8 giardin by bioinformatic analysis using DNAstar, Biosun and CLUSTAL W softwares. Each epitope was conjugated to keyhole limpethemocyanin (KLH) and then used to immunize female Chinchilla rabbits via multi-point（8-10 points） subcutaneous injections on the back（0.5 mg conjugate/rabbit, 100 μl at each point）. Then the rabbits were boosted（0.2 mg conjugate/rabbit） on days 14, 21 and 28 after the first immunization. Blood was collected prior to each immunization, and carotid artery blood（50 ml） was collected on day 7 after the last immunization. The antibody titer for anti-KLH-G1, anti-KLH-G2 and anti-KLH-G3 sera was determined with indirect ELISA. The reactivity of the three anti-sera with recominant giardin (rGiardin) was analyzed with Western blotting.The concentration of the purified conjugates KLH-G1, KLH-G2, and KLH-G3 was 0.66, 0.95 and 0.25 mg/ml， respectively. ELISA showed that the antibody titer for anti-KLH-G1, anti-KLH-G2 and anti-KLH-G3 sera was 1∶12800, 1∶51200, 1∶51200, respectively. SDS-PAGE revealed a specific band at M(r) 36 000 for the three anti-sera. Western blotting showed that the three anti-sera all specifically recognized rGiardin.Immunization with the KLH-G1, KLH-G2, and KLH-G3 conjugates induced production of specific IgG antibody in rabbits, which can recognize rGiardin.

Visible-light driven C-modified TiO2 film (C@TiO2 film) was prepared on a conducting substrate and studied as photoanode for photoelectrochemical and photoelectrocatalytic (PEC) properties. The as-prepared material was characterized by SEM, TEM, XRD, and diffuse reflectance spectra. The C@TiO2 film with multiporous structure exhibited enhanced electrochemical properties and excellent PEC performance, with a seven-fold improvement of photocurrent intensity as compared to unmodified TiO2. The PEC improvement may be resulting from extended visible light-harvesting, low electron transfer resistance, and promoted photocurrent response. This study could provide a new perspective on preparing high performance photoelectric catalyst films.

A strategy of the parasitic protozoan Giardia lamblia to evade attack from the host immune system is periodic changes of its surface antigen, a member of the variant surface protein (VSP) family. A post-transcriptional gene silencing mechanism has been proposed to explain the presence of only one among many possible VSPs at any time. To investigate this phenomenon further, we extracted total RNA from cultured trophozoites of the G. lamblia C2 isolate, and cDNA was reverse-transcribed from the RNA. Sense and anti-sense VSPs were amplified from the total cDNA using nested PCR with primers designed from the 3'-conserved region and the known 5' or 3' end of the cDNA library. Sequence analyses of the amplified products revealed more than 34 full-length antisense VSPs and a smear of sense VSPs. Sequence alignments and comparisons revealed that these VSPs contained variable N-termini and conserved C-termini, and could be classified into 5 clades based on the sizes and variations of the N-terminal sequence. All antisense VSPs existed in the sense forms, but no corresponding antisense VSP existed for sense RNA (snsRNA) 16. The coexistence of sense and antisense VSP mRNAs in cultured G. lamblia supports the post-transcriptional regulation of VSP expression. We propose that VSPs transcribed simultaneously in the sense and antisense forms form double-stranded RNAs (dsRNAs) which are degraded by the Dicer endonuclease, while a VSP without an antisense transcription (e.g., snsRNA16) will be expressed on the surface of Giardia. In addition, in the course of this investigation VSPs were identified that were previously not known. PCR-based amplification of specific sense and antisense VSP cDNAs can be used to identify the specific VSP on G. lamblia trophozoites, which is easier than using specific monoclonal antibody approaches.

Alpha8-giardin (α8-giardin) is a member of the multi-gene α-giardin family in the intestinal parasitic protozoan, Giardia lamblia. This gene family shares an ancestry with the annexin super family, whose common characteristic is calcium dependent binding to membranes that contain acidic phospholipids. In the present study, the antigenicity, hydrophilicity, flexibility, surface probability, and secondary structure of α8-giardin amino acids were predicted by bioinformatics applications. A specific anti-peptide antiserum, anti-P3, was used to determine the intracellular location of α8-giardin with confocal immunofluorescence microscopy and immunoelectron microscopy. The results indicated that α8-giardin was located on the plasma membrane and flagella, but not on the ventral disk. Reduction of α8-giardin transcript levels by ribozyme-mediated cleavage decreased trophozoite motility and growth rate, indicating the functional importance of α8-giardin to Giardia trophozoite biology.

Pneumocystis spp. infect the lungs of multiple mammalian species and cause disease in immunosuppressed individuals. The Pneumocystis isolates that have been studied to date fall into two major clades, those from primates and those from rodents. Within each of these clades, different species have been described on the basis of host specificity and differences in sequence and morphology. Here, we demonstrate that dexamethasone immunosuppression consistently results in histologically apparent lung infection in gerbils (28/35 animals). Sequence analysis of the 18S, 5.8S and internal transcribed spacer regions of the rDNA and a portion of the mitochondrial large subunit rDNA demonstrated that this gerbil Pneumocystis is grouped with other rodent Pneumocystis spp., but is distinct from them. Our results suggest that gerbil Pneumocystis differs sufficiently from Pneumocystis species found in other rodents to be considered a separate species.

To clarify the phylogenetic relationships and species status of Pneumocystis, the 5.8S rRNA gene and the internal transcribed spacers (ITS, 1 and 2) of Pneumocystis rRNA derived from rat, gerbil and human were amplified, cloned and sequenced. The genetic distance matrix of six Pneumocystis species compared with other fungi like Taphrina and Saccharomyces indicated that the Pneumocystis genus contained multiple species including Pneumocystis from gerbil. The phylogenetic tree also showed that Pneumocystis from human and monkey formed one group and four rodent Pneumocystis formed another group. Among the four members, Pneumocystis wakefieldiae was most closely related to Pneumocystis murina and Pneumocystis carinii, and was least related to gerbil Pneumocystis.

This article is a review of the latest information on the prevalence of G. lamblia in South Asia, South East Asia and Far East, characterizing the current endemic situation within these regions. Around 33 published papers from 2002-2007 were collected on G. lamblia. The included countries were Nepal, Bangladesh, India, Cambodia, Vietnam, Malaysia, Philippines, Indonesia, Thailand, Republic of Korea, and China. Only five published papers were discarded because data was extracted before 2002-2007 or they are not included within our regions, emphasizing more on G. lamblia in animals, or performed at extensive molecular level. The prevalence of G. lamblia varied markedly between studies illustrating higher levels in the urban than in the rural areas, more among poor communities, slightly higher in males than in females with age range of 2-5-year-old children, and among university students, old-aged people, HIV-positive patients, and gastric carcinoma patients. Though G. lamblia is not a life-threatening parasite, nevertheless, it is still considered as the most common water-borne diarrhea-causing disease. It is important to understand the etiology, frequency, and consequences of acute diarrhea in children. Routine surveillance such as bi-annual follow-up treatments, treating G. duodenalis cysts and other protozoa oocysts detected in ground water sources, and continuous health education are the most preventive measures.

To clone and express α8-giardin gene of Giardia lamblia, and analyze its immunoreactivity.The open reading frame (ORF) of α8-giardin gene was amplified by PCR. The PCR product was cloned into prokaryotic expression vector pET-30a (+) with restriction enzymes EcoR I and Xho I . The recombinant vector pET30a (+)-α8-giardin was transformed into E. coli BL21 (DE3), and the positive clones were then selected. The constructed pET30 a (+)-α8-giardin was induced with IPTG for expression, and purified through Ni-affinity chromatography. The recombinant protein was examined by SDS-PAGE and Western blotting.The length of α8-giardin gene was 930 bp. PCR and restriction enzyme digestion analysis confirmed the construction of recombinant plasmid pET30a (+)-α8-giardin. SDS-PAGE and Western blotting analysis showed that the recombinant protein rGiardin (about M, 36,000) was expressed in E. coli as inclusion body protein, and reacted positively with anti-His tag antibody and rabbit anti-G. lamblia serum.The recombinant plasmid pET30a (+)-α8-giardin is constructed, and the purified rGiardin protein shows immunoreactivity.

Control of structural and compositional characteristics during fabrication of a versatile visible-light active ZnO-based photocatalyst is a crucial step toward improving photocatalytic pollutant degradation processes. In this work, we report a multifunctional photocatalytic electrode, i.e., TiO2 coated ZnO:I nanorods (ZnO:I/TiO2 NRs) array films, fabricated via a hydrothermal method and a subsequent wet-chemical process. This type of hybrid photocatalytic film not only enhances light absorption with the incorporation of iodine but also possesses increased electron transport capability and excellent chemical stability arising from the unique TiO2-coated 1D structure. Owing to these synergic advantages, the degradation efficiency of the ZnO:I samples reached ∼97% after irradiation for 6 h, an efficiency 62% higher than that of pure ZnO. For RhB photocatalytic degradation experiments in both acidic (pH = 3) and alkaline (pH = 11) solutions, as well as in repeat photodegradation experiments, the ZnO:I/TiO2 NRs films demonstrated high stability and durability under visible-light irradiation. Thus, ZnO:I/TiO2 NRs are considered a promising photocatalytic material to degrade organic pollutants in aqueous eco-environments.

The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene, GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a approximately 100 aa longer central domain; a approximately 200 aa shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the "amitochondriate"G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G. lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia.

Giaridia lamblia was long considered to be one of the most primitive eukaryotes and to lie close to the transition between prokaryotes and eukaryotes, but several supporting features, such as lack of mitochondrion and Golgi, have been challenged recently. It was also reported previously that G. lamblia lacked nucleolus, which is the site of pre-rRNA processing and ribosomal assembling in the other eukaryotic cells. Here, we report the identification of the yeast homolog gene, krr1, in the anucleolate eukaryote, G. lamblia. The krr1 gene, encoding one of the pre-rRNA processing proteins in yeast, is actively transcribed in G. lamblia. The deduced protein sequence of G. lamblia krr1 is highly similar to yeast KRR1p that contains a single-KH domain. Our database searches indicated that krr1 genes actually present in diverse eukaryotes and also seem to present in Archaea. However, only the eukaryotic homologs, including that of G. lamblia, have the single-KH domain, which contains the conserved motif KR(K)R. Fibrillarin, another important pre-rRNA processing protein has also been identified previously in G. lamblia. Moreover, our database search shows that nearly half of the other nucleolus-localized protein genes of eukaryotic cells also have their homologs in Giardia. Therefore, we suggest that a common mechanism of pre-RNA processing may operate in the anucleolate eukaryote G. lamblia and in the other eukaryotes and that like the case of "lack of mitochondrion," "lack of nucleolus" may not be a primitive feature, but a secondarily evolutionary condition of the parasite.

In addition to its medical importance as parasitic pathogen,Entamoeba has aroused people’s interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to typical eukaryotes,Entamoeba and several other amitochondrial protozoans have been recognized as ancient premitochondriate eukaryotes and named “archezoa”, the most primitive extant eukaryotes. It was suggested that they might be living fossils that remained in a primitive stage of evolution before acquisition of organelles, lying close to the transition between prokaryotes and eukaryotes. However, recent studies revealed thatEntamoeba contained an organelle, “crypton” or “mitosome”, which was regarded as specialized or reductive mitochondrion. Relative molecular phylogenetic analyses also indicated the existence or the probable existence of mitochondrion inEntamoeba. Our phylogenetic analysis based on DNA topoisomerase II strongly suggested its divergence after some mitchondriate eukaryotes. Here, all these recent researches are reviewed and the evolutionary status ofEntamoeba is discussed.

To inhibit the expression of pyruvate kinase (PK) mRNA in Giardia lamblia by specific hammerhead ribozyme.The constructed hammerhead-GCV vector (pGCV-PKH) which aims to PK mRNA was electroporated into G. lamnblia trophozoites (group A). Electroporated trophozoites (group B) and normal trophozoites (group C) served as control Trophozoites in each group were collected at 24, 48, 72 and 96 h post-electroporation, respectively. The concentrations of trophozoites were calculated and the growth curves were constructed. At 24, 48, 72 and 96 h post-electroporation, mRNA of each group was detected by RT-PCR and real-time PCR, respectively. The PK activity was tested by ultraviolet spectrophotometry.The growth curve showed that the growth of trophozoites was considerably depressed after 96 h post-electroporation. RT-PCR result displayed that the specific ribozyme mRNA was detected in group A from 24 h to 96 h post-electroporation. At 24 and 48 h after transfection, the PK mRNA level of group A decreased to 5% (5 +/- 0.17) and 8% (8 +/- 0.19) of the level in group C, respectively; and the PK activity of group A decreased to 32% (32 +/- 0.64) and 38% (38 +/- 0.65) of the level in group C.PK mRNA expression in G. lamblia has been inhibited by specific hammerhead ribozyme.

Mitosis of Giardia lamblia is a complex and rapid event that is poorly understood at the cellular and molecular levels. Therefore, we conducted this study to determine (1) whether the two nuclei have similar or different chromosomes, (2) the number of chromosomes of G. lamblia, and (3) the morphology and karyotype of the chromosomes. Trophozoites of the C2 and WB strains of G. lamblia were grown in modified TYI-S-33 medium at 37°C. The trophozoites were collected, and sample slides were prepared for conventional light and scanning electron microscopy. Light microscopy revealed five pairs of chromosomes. The chromosomes were approximately 0.64–0.94 μm long with a short rod-like shape and were usually arranged in pairs. Scanning electron microscopy yielded similar findings, and 10 chromosomes could be seen in each nucleus. Thus, the chromosome number of G. lamblia is 2n = 10. Chromosomes in pair 1 are submetacentric chromosomes, while pairs 2–5 are telocentric chromosomes. The present study shows that G. lamblia trophozoites have typical condensed chromosomes during mitosis and contains five pairs of chromosomes. The karyogram shows good fit to the formula 2n = 10 = 2sm + 8t revealed by scanning electron microscopy.

To construct a recombinant vector of Giardia canis virus (GCV)-specific hammerhead ribozyme of pyruvate kinase (PK) in Giardia lamblia.Using RNA draw software, the secondary structure of PK gene in Giardia was predicted and the cleavage site of ribozyme was selected. The antisense-specific hammerhead ribozyme (PKH) targeting this site was designed. The DNA encoding the ribozyme was synthesized and the recombinant vector pGCV-PKH was constructed. The extracellular and intracellular cleavage of PK mRNA was carried out with the linear recombinant vector. Trophozoites in each group were observed with fluorescent microscopy at 24th hour after transfection. Real-time PCR was used for relative quantitative analysis of cleavage products.The recombinant vector of GCV-specific hammerhead ribozyme of pyruvate kinase in Giardia lamblia (pGCV-PKH) was constructed. Intracellular cleavage assays showed that the green fluorescence could only be seen in pGCV-GFP transfected trophozoites. The relative content of PK mRNA in pGCV-PKH transfected group was 33.14% of that in normal control group. It could cleave PK mRNA extracellularly and the efficiency was 58.5%.The recombinant vector can transfect Giardia trophozoites, and cleave mRNA of PK intracellularly and extracellularly.

Giardia species are flagellated parasites of vertebrates and belong to the diplomonads, most of which have two nuclei. These organisms were classified among the earliest branching eukaryotes on the basis of small subunit rDNA sequences and their lack of many canonical organelles. However, some of these organelles have subsequently been identified in rudimentary form, such as Golgi that become apparent during encystation. One of the "missing" organelles has been the nucleolus, the site of rRNA synthesis, since it was not identified in earlier ultrastructural studies. In the current study, we visualized in-vitro-grown Giardia lamblia trophozoites by transmission electron microscopy and laser scanning confocal microscopy. We found that each of the two nuclei contains a single small and deeply stained granular nucleolus, thus demonstrating that Giardia does indeed have nucleoli.

Several anti-Giardia drugs, such as metronidazole, tinidazole, mebendazole, albendazole and furazolidone, are usually effective but have severe side effects and potential toxicity. An urgent need exists for more effective and less toxic agents that can act against this protozoan. For this purpose, the effects of dihydroartemisinin (DHA) on Giardia lamblia were investigated in vitro. Axenically grown G. lamblia trophozoites were treated with DHA (LD(50) = 200 microg/mL) at different time intervals. The morphological and ultrastructural changes of the treated trophozoites were observed by both light and transmission electron microscopy (TEM). Changes in the cell cycle of the treated cells were observed by flow cytometry. By light microscopy, we observed that DHA-treated trophozoites were detached from the wall of the culture tube and shown bradypraxia and bubbles in the dorsal and ventral surfaces. Ultrastructural observations by TEM revealed that DHA promoted modifications of the cell shape, pronounced dorsal vesiculation, plasma membrane blebbing, disaggregation of ribosomes, depletion of cytoplasmic matrix and heavy deposition of electron-dense precipitates on the cytoplasm and nucleus. The main changes observed in the treated group included the following: (1) trophozoites were rounder in shape and the endoplasmic reticulum was dilated, (2) enlarged trophozoites contained lamella structures and deformed nuclei, (3) trophozoites displayed dissolved cytoplasm with large vacuole spaces or decreased cytoplasmic volume, (4) adhesive disc bubbles or the lamella structures of cytoplasm were clearly observed, and (5) cell division was arrested. Using microscopy and cytometry techniques, we demonstrate that changes in G. lamblia morphology and cell cycle state were induced by DHA.

Giardia lamblia is an early branching eukaryotic microorganism that derives its metabolic energy primarily from anaerobic glycolysis. In most organisms, glycolysis is catalyzed by pyruvate kinase (PK), allowing the generation of two ATP molecules from one molecule of pyruvate. Giardia has both PK and pyrophosphate-dependent pyruvate phosphate dikinase (PPDK), which catalyzes the generation of five ATP molecules from pyruvate by pyrophosphate-dependent glycolysis and offers a potential selective advantage. In order to evaluate the importance of pyrophosphate-dependent glycolysis, we used ribozyme-mediated cleavage of the PPDK transcript to decrease PPDK transcript levels to 20% of normal. The accompanying decrease in PPDK enzyme activity decreased ATP levels to 3% of normal and increased glycogen deposition, confirming the importance pyrophosphate-mediated glycolysis that was previously suggested by cell lysate studies. PPDK is not found in vertebrates, so specific inhibitors may be useful for treatment of infections caused by anaerobic protists that depend on pyrophosphate-dependent glycolysis.

To analyze the genetic characteristics of two rabies virus isolates from Henan province and to compare their relations hip with known rabies virus isolates and vaccine strains.Rabies viral antigens were detected in 100 canine brains by immunofluorescence assay method. Rabies virus was isolated through inoculating the suspensions of positive brains into suckling mice. N gene and G were amplified by RT-PCR and sequenced. Phylogenetic trees were constructed for the analysis on genetic characteristics of rabies virus.Two rabies virus strains were isolated (Henan Hb1 and Henan Sq1). Data from sequential comparison revealed that the nucleotide and amino acid identities of N and G gene between the two isolates were 99.3% and 98.9%, and 98.7% and 98.4% respectively. The two isolates were more closely related to CTN, with the homogeny of N gene and G gene as 89.1% and 85.6%-85.7% at the nucleotide level, but 97.6%-98.0% and 92.3% at the amino acid level respectively, than to other vaccine strains. When comparing with other known viruses including Chinese isolates, the two stains shared closer identity with the isolates from Indonesia, and the rates of homogeny of N and G gene were 92.1%-93.2% and 91.9%-92.1% at the nucleotide level, 97.5%-98.6% and 96.0%-96.2% at the amino acid level, respectively. Data from the deduced amino acid sequences revealed that some amino acid residues including the residues in the N and G antigenic sites were substituted in the two isolates. Furthermore, phylogenetic analysis showed that the two isolates were also more closely related to the strains from Indonesia and vaccine strain CTN than to any other known street viruses and vaccine strains.Both Henan Hbl and Henan Sql belonged to genotype 1. However, the N and G gene diverged from known street viruses and vaccine strains at either nucleotide level or amino acid level.

To establish axenic cultivation of Pneumocystis carinii (P.c).The organisms of P.c were isolated from the bronchoalveolar lavage fluid (BALF) of the rats with Pneumocystis carinii pneumonia (PCP) and cultured in a medium which was based on IMDM(GIBCO) supplemented with S-adenosyl-L-methionine, putrescine, N-acetyl glucosamine, putrescine, L-cysteine and L-glutamine, and newborn calf serum. The organisms cultured in the system were identified by observing the morphology of cysts in smears stained with Gomori's methenamine silver nitrate stain (GMS). Ultrastructure of the cysts/trophozoites was examined by transmission electron microscopy. The sequences of mitochondrial large ribosomal DNA subunit of the cultured organisms were compared with the Pneumocystis carinii f.sp. ratti variant isolate (GenBank No U20173) and Pneumocystis carinii f.sp.hominis (GenBank No M58605).Five isolates of P. carinii received from BALF of 8 rats with PCP were cultured axenically and continuously in the system. The cultured organisms could be stored in frozen condition and used to reinitiate culture, and were amplified by 19-22 times within 72 h. The morphology, ultrastructure and gene sequencing of the cultured organisms confirmed that the isolated organisms were P. carinii.Five continuously and axenicly cultured isolates of P. carinii have been received.

Trophozoites of Giardia lamblia were axenically cultivated with modified TYI-S-33 medium contained 500 microg/ml metronidazole (12h LC50). The morphology of drug-treated trophozoites was observed with light and electron micro-scopes at 2, 4, 8, 12 h respectively. The light microscopy revealed that the trophozoites treated with MTZ showed swollen, detached from the wall of the culture tube, and were with vacuoles in the cytoplasm. Movement of the flagella become slowly or stopped. Electronic microscopy showed that the trophozoites were swollen and deformed; lots of vacuoles were seen in the cytoplasm; the contents of cytoplasm were depleted and the nuclei deformed. This study indicated that MTZ has injured the morphology of G. lamblia.

To establish genetic method in detecting Cryptosporidium parvum and Giardia lamblia which often coinfected with AIDS patients.Cryptosporidium oocysts and Giardia cysts were isolated and purified from fecal samples of the individuals infected with C. parvum and G. lamblia, respectively. Genomic DNAs were extracted. Two pairs of specific primers were designed or synthesized according to the 18S rRNA gene from C. parvum or the triose phosphate isomerase (tim ) gene from G. lamblia. Polymerase chain reaction(PCR) technique was used to amplify the DNA samples from the oocysts and the cysts, and those from the 6 control samples, including Schitosoma japonicum, Toxoplasma gondii , Entamoeba histolytica, Trichinella spiralis, Trichomonas vaginalis and human blood cells. DNA samples from 30 fecal samples of AIDS patients were detected with the same method.One fragment of 500 bp was amplified with the primer of C. parvum, and the other one of 683 bp was amplified with the primer of G. lamblia. Twenty pg and 0.4 pg DNA of C. parvum and G. lamblia could be detected separately. The specificity of these two pairs of PCR primers was confirmed by the failure in the amplification of the control DNA samples. Out of 30 cases of AIDS patients, 7 showed C. parvum positive, while non Giardia was detected.Genetic detection method for C. parvum and G. lamblia detection was established which was more sensitive and specific.