Temperature-Tolerant Versatile Conductive Zwitterionic Nanocomposite Organohydrogel toward Multisensory Applications.

Conductive hydrogels (CHs) are emerging materials for next generation sensing systems in flexible electronics. However, the fabrication of competent CHs with excellent stretchability, adhesion, self-healing, photothermal conversion, multisensing, and environmental stability remains a huge challenge. Herein, a nanocomposite organohydrogel with the above features is constructed by in situ copolymerization of zwitterionic monomer and acrylamide in the existence of carboxylic cellulose nanofiber-carrying reduced graphene oxide (rGO) plus a solvent displacement strategy. The synergy of abundant dipole-dipole interactions and intermolecular hydrogen bonds enables the organohydrogel to exhibit high stretchability, strong adhesion, and good self-healing. The presence of glycerol weakens the formation of hydrogen bonds between water molecules, endowing the organohydrogel with excellent environmental stability (-40 to 60 °C) to adapt to different application scenarios. Importantly, the multimodal organohydrogel presents excellent sensing behavior, including a high gauge factor of 16.3 at strains of 400-1440% and a reliable thermal coefficient of resistance (-4.2 °C-1) over a wide temperature widow (-40 to 60 °C). Moreover, the organohydrogel displays a highly efficient and reliable photothermal conversion ability due to the favorable optical absorbing behavior of rGO. Notably, the organohydrogel can detect accurate human activities at ambient temperature, demonstrating potential applications in flexible intelligent electronics.

An 'active site anchoring' strategy for the preparation of PBO fiber derived carbon catalyst towards an efficient oxygen reduction reaction and zinc-air batteries.

In order to promote the wide application of clean energy-fuel cells, it is urgent to develop transition metal-based high-efficiency oxygen reduction reaction (ORR) catalytic materials with a low cost and available rich raw material resources to replace the currently used precious metal platinum-based catalytic materials. Herein, a novel 'active-site-anchoring' strategy was developed to synthesize highly-activated carbon-based ORR catalysts. Firstly, poly(p-phenylene benzobisoxazole) (PBO) fiber with a stable chemical structure was selected as the main precursor, and iron was complexed on its surface, and then poly-dopamine (PDA) was coated on the surface of PBO-Fe to form a PBO-Fe-PDA composite structure. Therefore, carbon-based catalyst PBO-Fe-PDA-900 with abundant Fe2O3 active sites was prepared by anchoring iron sites by PDA after pyrolysis. As a result, the PBO-Fe-PDA-900 catalyst displayed a 30 mV higher half-wave potential (0.86 V) than that of a commercial Pt/C electrocatalyst. Finally, PBO-Fe-PDA-900 was used as a cathode material for zinc-air batteries, showing a high peak power density superior to Pt/C. This work offers new prospects for the design of efficient, non-precious metal-based materials in zinc-air batteries.

Construction of Functionalized α-Imino Ketones via Pd-Catalyzed C-H Addition to Nitriles/Aerobic Oxidation Sequences.

Pd(II)-catalyzed addition of sp2 C-H to nitrile/aerobic oxidation sequences for the preparation of functionalized α-imino ketones is described in which readily available heteroarenes and O-acyl cyanohydrins were employed. Various functionalized targeted molecules can be prepared in good yields with high atom and step economy. Moreover, a broad substrate scope and the ready manipulation and availability of the reaction partners enable this protocol to be appealing to explore the chemical space of the construction of functionalized α-imino ketones with high efficiency.

Grafting macromolecular chains on the surface of graphene oxide through crosslinker for antistatic and thermally stable polyethylene terephthalate nanocomposites.

The graphene oxide (GO) and polyethylene terephthalate (PET) molecular chains are connected together by the two amino groups of the crosslinking agent p-phenylenediamine (PPD). The presence of macromolecular chains could make GO uniformly dispersed in the polymer matrix, improving the antistatic performance and thermal stability of the nanocomposite. In this paper, GO was prepared by the improved Hummers, method. In the first step, an amine group of PPD undergoes a nucleophilic ring-opening reaction with an epoxy group on GO. Multiple characterization methods indicate that PPD is successfully grafted to the surface of GO sheets and GO is partially reduced simultaneously. The graphene layer spacing increased from 0.81 nm for GO to 1.49 nm for grafted graphene oxide (g-GO). The number of oxygen-containing functional groups in GO is also reduced. The conductivity of g-GO at room temperature is 1.8 S cm-1, which is much higher than that of GO. In addition, the thermal stability of g-GO has also been improved. In the second step, the other unreacted terminal amino group of PPD is grafted to PET molecular chains through hydrogen bonding or amidation reactions. Antistatic and thermally stable nanocomposites were then obtained by hot pressing. Different ratios of graphene/polyester nanocomposites were obtained. At the same time, the g-GO is further thermally reduced. The thermal stability of PET/g-GO nanocomposite has been greatly improved, while the thermal stability of PET/GO nanocomposite is basically the same as that of pure PET. For the PET/g-GO nanocomposite, the residue rate has increased by nearly 10%, and the maximum thermal decomposition temperature has also increased by 11 °C. When the content of g-GO is 1.0 vol%, the bulk conductivity of PET/g-GO nanocomposite is increased by 8 orders of magnitude. However, when the content of GO is 1.0 vol%, the bulk conductivity of the PET/GO nanocomposite is only improved by 3 orders of magnitude. PET/g-GO nanocomposites exhibit good antistatic properties. The PET/g-GO nanocomposite's conductive percolation threshold is 0.61 vol%, while that of the PET/GO nanocomposite is 1.64 vol%. The electrical conductivity of the nanocomposite increases with the increase of graphene content. And the well-dispersed modified graphene can improve the electrical conductivity of the nanocomposite.

Enhancement of Output Performance of Triboelectric Nanogenerator by Switchable Stimuli in Metal-Organic Frameworks for Photocatalysis.

Precise control of the structure of crystalline materials is an efficient strategy to manipulate the fundamental performance of solids. In metal-organic framework (MOF) materials, this control can be realized by reversible cation-exchange through chemically driven changes in the crystalline state. Herein, we reported that the reversible structural transformations between an anionic Zn-MOF (1) and a topologically equivalent bimetallic Zn/Co-MOF (2) were accomplished. Both MOFs powders and their hybrid composites were used as positive electrode materials to assemble triboelectric nanogenerators (TENGs). The results demonstrated that the output performance of the Zn/Co-MOF-TENG was effectively improved because the introduction of Co ions makes electron transfer easier. Moreover, the output performance of the TENGs based on MOF@PVDF (PVDF = polyvinylidene fluoride) composite films showed that the Zn/Co-MOF@PVDF-TENG possessed much higher output than these corresponding film-based and MOF-based TENGs. As a practical application, the superior output of Zn/Co-MOF@PVDF-TENG was used to light an ultraviolet lamp plate for the [2 + 2] photochemical cycloaddition of organometallic macrocycles.

Venous thoracic outlet syndrome.

Venous thoracic outlet syndrome (vTOS) is a spectrum of disease caused by external compression of the subclavian vein as it passes through the costoclavicular space. Paget-Schroetter's Syndrome (PSS) or effort thrombosis is a subtype of vTOS where compression and microtrauma to subclavian vein from repetitive arm movements results in venous thrombosis. PSS or effort thrombosis mostly affects young otherwise healthy active individuals, and this further highlights the importance of this condition. Early diagnosis and aggressive early intervention aimed at complete resolution of acute symptoms and minimizing the risk of recurrence is ultimately important and increases the likelihood of the full restoration of limb function. Several noninvasive imaging techniques are currently available to confirm the initial diagnosis including Doppler ultrasound, contrast-enhanced computed tomography, and magnetic resonance imaging. Following diagnosis, multiple algorithms exist for the management of PSS and almost all require a multidisciplinary approach. Like any other condition involving the thrombosis of deep venous system, initial step in the management is anticoagulation. Catheter-directed therapies (CDT) have also a pivotal role as the initial treatment to resolve the acute thrombosis and establish venous patency. CDT combined with medical anticoagulation and surgical decompression are the components of most treatment algorithms for the management of patients suffering from PSS.

Radiolabeling strategies and pharmacokinetic studies for metal based nanotheranostics.

Radiolabeled metal-based nanoparticles (MNPs) have drawn considerable attention in the fields of nuclear medicine and molecular imaging, drug delivery, and radiation therapy, given the fact that they can be potentially used as diagnostic imaging and/or therapeutic agents, or even as theranostic combinations. Here, we present a systematic review on recent advances in the design and synthesis of MNPs with major focuses on their radiolabeling strategies and the determinants of their in vivo pharmacokinetics, and together how their intended applications would be impacted. For clarification, we categorize all reported radiolabeling strategies for MNPs into indirect and direct approaches. While indirect labeling simply refers to the use of bifunctional chelators or prosthetic groups conjugated to MNPs for post-synthesis labeling with radionuclides, we found that many practical direct labeling methodologies have been developed to incorporate radionuclides into the MNP core without using extra reagents, including chemisorption, radiochemical doping, hadronic bombardment, encapsulation, and isotope or cation exchange. From the perspective of practical use, a few relevant examples are presented and discussed in terms of their pros and cons. We further reviewed the determinants of in vivo pharmacokinetic parameters of MNPs, including factors influencing their in vivo absorption, distribution, metabolism, and elimination, and discussed the challenges and opportunities in the development of radiolabeled MNPs for in vivo biomedical applications. Taken together, we believe the cumulative advancement summarized in this review would provide a general guidance in the field for design and synthesis of radiolabeled MNPs towards practical realization of their much desired theranostic capabilities. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Diagnostic Nanodevices Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Flexible, Robust, and Multifunctional Electromagnetic Interference Shielding Film with Alternating Cellulose Nanofiber and MXene Layers.

Flexible, lightweight, robust, and multifunctional characteristics are greatly desirable for next-generation wearable electromagnetic interference (EMI) shielding materials. In this work, an alternating multilayered structure with robust polymer frame layers and directly contacted conducting layers was designed to prepare high-performance EMI films. Especially, the multilayered films containing alternating cellulose nanofiber (CNF) layers and MXene layers are fabricated via a facile and efficient alternating vacuum filtration approach. Deriving from the mechanical frame effect acted by CNF layers in, which is capable of preventing the nanosized "zigzag" crack in MXene layers from growing to the whole film, the alternating multilayered film (CNF@MXene) revealed the improved mechanical strength (112.5 MPa) and toughness (2.7 MJ m-3) compared to both freestanding MXene film and homogeneous CNF/MXene film. Meanwhile, the directly contacted MXene layers resulted in the increased electrical conductivity from 2 (homogeneous CNF/MXene film) to 621-82 S m-1 (CNF@MXene films). In conjunction with the extra "reflection-absorption-zigzag reflection" mechanism among the alternating multilayers, CNF@MXene films demonstrated an exceptional EMI shielding effectiveness of ∼40 dB in the X-band and K-band and high specific shielding effectiveness up to 7029 dB cm2 g-1 at a thickness of only 0.035 mm. Besides, the excellent mechanical flexibility ensured the stable EMI shielding and electrical properties, which can withstand the folding test more than 1000 times without obvious reduction. Moreover, the excellent electrical conductivity endows the alternating multilayered film with an outstanding and steady Joule heating performance, which could reach more than 100 °C at only 6 V impressed voltage to within 10 s. As a result, our alternating multilayered film with reinforced EMI shielding and Joule heating performance is promising in the next-generation intelligent protection devices applying in cold and complex practical environments.

Superhydrophobic Electrically Conductive Paper for Ultrasensitive Strain Sensor with Excellent Anticorrosion and Self-Cleaning Property.

Recently, a paper-based (PB) strain sensor has turned out to be an ideal substitute for the polymer-based one because of the merits of renewability, biodegradability, and low cost. However, the hygroexpansion and degradation of the paper after absorbing water are the great challenges for the practical applications of the PB strain sensor. Herein, the superhydrophobic electrically conductive paper was fabricated by simply dip-coating the printing paper into the carbon black (CB)/carbon nanotube (CNT)/methyl cellulose suspension and hydrophobic fumed silica (Hf-SiO2) suspension successively to settle the problem. Because of the existence of ultrasensitive microcrack structures in the electrically conductive CB/CNT layer, the sensor was capable of detecting an ultralow strain as low as 0.1%. During the tension strain range of 0-0.7%, the sensor exhibited a gauge factor of 7.5, almost 3 times higher than that of the conventional metallic-based sensors. In addition, the sensor displayed frequency-independent and excellent durability and reproductivity over 1000 tension cycles. Meanwhile, the superhydrophobic Hf-SiO2 layer with a micro-nano structure and low surface energy endowed the sensor with outstanding waterproof and self-cleaning properties, as well as great sustainability toward cyclic strain and harsh corrosive environment. Finally, the PB strain sensor could effectively monitor human bodily motions such as finger/elbow joint/throat movement and pulse in real time, especially for the wet or rainy conditions. All these pave way for the fabrication of a high-performance PB strain sensor.

Ultrasensitive and Highly Compressible Piezoresistive Sensor Based on Polyurethane Sponge Coated with a Cracked Cellulose Nanofibril/Silver Nanowire Layer.

With the rapid development of flexible wearable electronics, a piezoresistive sensor with low detection limit and wide strain sensing range turns out to be a great challenge for its application in this field. Here, a cracked cellulose nanofibril/silver nanowire (CA) layer-coated polyurethane (PU) sponge was acquired through a simple dip-coating process followed by precompression treatment. The electrical conductivity and mechanical property of the conductive CA@PU sponge could be effectively tuned through changing the dip-coating number. As a piezoresistive sensor, the sponge exhibited the capability of detecting both small and large motions over a wide compression strain range of 0-80%. Based on the "crack effect", the sensor possessed a detection limit as low as 0.2% and the gauge factor [GF, GF = (Δ R/ R0)/ε, where Δ R, R0, and ε represent the instantaneous resistance change, original resistance, and strain applied, respectively] was as high as 26.07 in the strain range of 0-0.6%. Moreover, the "contact effect" enabled the sensor to be applicable for larger strain, and the GF decreased first and then became stable with increasing compression strain. In addition, frequency- and strain-dependent sensing performances were observed, demonstrating that the sensor can respond reliably to different applied frequencies and strains. Furthermore, the sensor displayed exceptional stability, repeatability, and durability over 500 cycles. Finally, the sensor could be applicable for the detection of various human bodily motions, such as phonation, stamping, knee bending, and wrist bending. Most importantly, the sponge also exhibited great potential for the fabrication of artificial electronic skin. Herein, the conductive CA@PU sponge will undoubtedly promote the development of high-performance flexible wearable electronics.

pH and Thermal Dual-Responsive Graphene Oxide Nanocomplexes for Targeted Drug Delivery and Photothermal-Chemo/Photodynamic Synergetic Therapy.

The development of versatile nanoplatforms with efficient tumor-targeting properties and synergistic therapeutic strategies to realize effective antitumor efficiency are highly anticipated in the field of cancer therapy. Herein, we innovatively synthesized targeted nanocomplexes (NCGO-FA) with nanoscale structures by a modified Hummers' method and then used these nanocomplexes to separately load the doxorubicin (DOX) and methylene blue (MB) via π-π stacking, electrostatic attractions, and/or hydrophobic interactions, forming NCGO@DOX-FA and NCGO@MB-FA nanoplatforms. The results demonstrated that the NCGO-FA nanocomplexes have an ultrahigh surface area, a high-load content of drugs, targeting specificity, and a good photothermal conversion efficiency and photostability. Meanwhile, after loading the nanoplatforms with DOX or MB, NCGO-FA delivered drugs into cancer cells by folic acid (FA) receptors and triggered the drug release by heat and in acidic tumor environments. More importantly, compared with individually applied photothermal therapy, photodynamic therapy, or chemotherapy, the photothermal-chemo or photothermal-photodynamic synergistic therapy with the NCGO@DOX-FA or NCGO@MB-FA nanoplatform exhibits a remarkable synergistic effect, resulting in a distinguished antitumor efficiency. Consequently, this work proposes a facile and versatile method to construct a dual-responsive versatile nanoplatform that combines photothermal-chemo and photodynamic therapies, and these nanoplatforms have excellent application prospects for tumor therapy.

Clinical Predictors of Port Infections in Adult Patients with Hematologic Malignancies.

PURPOSE: To identify clinical predictors of port infections in adult patients with hematologic malignancies. MATERIALS AND METHODS: A retrospective chart review identified 223 adult patients (age ≥ 18 y) with hematologic malignancies, including lymphoma (n = 163), leukemia (n = 49), and others (n = 11), who had a port placed from 2012 to 2015. Early (< 30 d after port placement) and overall port infections (bloodstream and site infections) were recorded. To elucidate clinical predictors for early and overall port infections, proportional subdistribution hazard regression (PSHREG) analyses were conducted with variables including patients' demographics, medications used, laboratory data, and port characteristics. RESULTS: Total duration of follow-up was 83,722 catheter-days (median per patient, 274 catheter-days). Early and overall port infections were identified in 8 (3.6%) and 26 (11.7%) patients, respectively. Early and overall infection rates were 1.2 and 0.3 infections/1,000 catheter-days, respectively. Backward stepwise multivariate PSHREG analyses identified hypoalbuminemia (< 3.5 mg/dL) at the time of port placement (hazard ratio = 5.03; 95% confidence interval, 1.14-22.16; P = .03) and steroid use (> 30 d cumulatively during follow-up period) (hazard ratio = 3.41; 95% confidence interval, 1.55-7.47; P = .002) as independent risk factors for early and overall port infections, respectively. CONCLUSIONS: In adult patients with hematologic malignancies, hypoalbuminemia at the time of port placement was a clinical predictor for early port infections, whereas steroid use was a clinical predictor for overall port infections.

[Survey of infection situation of intestinal parasites of rural residents in plain area of Shandong Province].

OBJECTIVE: To understand the current situation of infections of intestinal parasites of rural residents in four cities namely Dongying, Weifang, Jining and Heze of Shandong Province. METHODS: Twenty-four villages were randomly selected as study areas. The Kato-Katz technique was applied to test the stool samples of adult residents and the cellophane tape anus method was applied to test the infection of Enterobius vermicularis of children aged 12 years or below. Fifty families were randomly selected from each village and surveyed with questionnaires for the general situation of the family, and the knowledge of prevention and control of parasites, and healthy behaviors of the family members. RESULTS: Totally 8,227 adult residents and 1,313 children were investigated and the total infection rate of intestinal parasites was 0.55% (45 cases). The infection rates of Ascaris lumbricoides, hookworm, Trichuris trichura, E. vermicularis and Clonorchis sinensis were 0.15% (12 cases), 0.06% (5 cases), 0.09% (7 cases), 1.37% (18 cases) and 0.04% (3 cases), respectively. Totally 3,767 residents were surveyed with questionnaires, and the awareness rate of the knowledge of prevention and control of parasites was 28.72% (1,082 cases), the formation rates of washing hands before meal, washing hands after toilet, washing fruit and vegetables before eating, and never drinking unboiled water were 60.66% (2,285 cases), 50.17% (1,890 cases), 48.71% (1,835 cases), and 87.07% (3,280 cases), respectively. CONCLUSION: In the plain area of Shandong Province, the infection rates of A. lumbricoides, hookworm, T. trichura and C. sinensis are low but the infection rate of E. vermicularis of children is relatively high; the awareness rates of the knowledge of parasites as well as the formation rates of healthy behaviors are low. Therefore, the health education and promotion should be strengthened.

[Survey of intestinal parasitic infections and related knowledge and behavior of residents in Jiaodong area of Shandong Province].

OBJECTIVE: To understand the status of intestinal parasitic infections and the related knowledge and behavior in residents of Jiaodong area of Shandong Province, so as to provide the evidence for making an appropriate preventive and control strategy. METHODS: A total of 18 villages from 6 counties in Jiaodong area were selected as investigation sites according to the stratified sampling method. The feces samples of the permanent residents aged above 3 years were collected and examined by Kato-Katz technique to find the intestinal parasite eggs, and the children under 12 years old were examined by the method of cellophane anal swab to detect the Enterobius vennrmicularis eggs. In addition, 50 households in each survey sites were randomly selected to investigate the basic family situation and the condition of awareness on prevention knowledge and formation of correct behavior of residents by using a structured questionnaire. RESULTS: Totally 6 163 residents involved in the feces examinations, and the total infection rate of intestinal parasites was 6.91%. The infection rates of Trichuris trichiura, Ascaris lumbricoides and hookworm were 6.56%, 0.62% and 0.21%, respectively. The infection rate of E. vermicularis in children under 12 years old was 0.51%. The eggs of Clonorchis sinensis and Taenia solium were not found in this survey. The awareness rate of knowledge about preventing parasitic diseases was 49.54%. The formation rates of washing hands before eating, washing hands after using the toilet, never eating raw fruit and vegetable without washing clean, never working in the field with bare feet, and never drinking unboiled water were 97.78%, 91.95%, 88.81%, 92.42% and 86.48% respectively. CONCLUSIONS: The infection rate of intestinal parasites is low in Jiaodong area, but there is a significant difference among different counties. The awareness rate of knowledge about preventing parasitic diseases is low, but the formation rate of healthy behavior is high. In the future, the health education and the strategy of taking medicine among the key population should be enhanced, and the project of reconstructing safe water supply and lavatory should be advanced.

[Analysis of results of technique competition for diagnosis of parasitic diseases in Shandong Province].

OBJECTIVE: To understand the capacity of Plasmodium detection and helminth detection and the mastery degree of basic knowledge of parasitic diseases. METHODS: Three professionals from each city were selected as contestants. The content of the competition contained three parts. The first part included making blood slides and Giemsa staining of Plasmodium, and identification of species and number with microscopy, the second part included making stool slides with Kato-Katz technique and identification of common helminth eggs with microscopy, and the third part was basic knowledge of parasitic diseases. RESULTS: Totally 51 contestants took part in the competition. The average score of the test of making blood slides was 14.8 +/- 3.3, and the passing rate was 82.4%. The average score of the identification of species and number of Plasmodium with microscopy was 19.2 +/- 9.3, and the passing rate was 29.4%. The average score of the test of making stool slides was 9.3 +/- 0.7, and the passing rate was 100%. The average score of the identification of common helminth eggs with microscopy was 28.0 +/- 2.6, and the passing rate was 100%. The average score of basic knowledge of parasitic diseases was 76.3 +/- 11.9, and the passing rate was 88.2%. The average score of the test of making blood slides in the female was higher than that in the male (15.7vs.13.5, P < 0.05), and the average score of the test of making blood slides in the intermediate title contestants was higher than that in the junior title contestants (16.1 vs.14.1, P < 0.05). The average score of the basic knowledge of parasitic diseases in the contestants from cities was higher than that in the contestants from towns (83.2 vs. 72.6, P < 0.05), and the average score of basic knowledge of parasitic diseases in the contestants from high economic level cities was higher than that in the contestants from low economic level cities (82.4 vs. 71.5, P < 0.01). CONCLUSIONS: For professionals in Shandong Province, the capacity of helminth detection was strong and the basic knowledge of parasitic diseases was mastered well, while the capacity of Plasmodium detection was weak.

[Control strategy and practice of soil-transmitted parasitic diseases in Shandong Province].

OBJECTIVE: To explore the sustainable development control strategies on soil-transmitted parasitic diseases appropriate to current epidemic characteristics so as to effectively reduce the epidemic level and harm to people in Shandong Province. METHODS: This project was led by the Shandong Medical Department, governed and instructed by the Shandong Institute of Parasitic Diseases, concretely implemented by the centers for disease control and prevention in counties or cities. All the work was carried out according to the Control Programming of National Key Parasitic Diseases, and with the combination of routine and key control strategies according to the actual situation. RESULTS: The average infection rate of soil-transmitted parasitic diseases in Shandong Province was 18.26% in 2003. During the 2007 to 2009 period, 3,115,194 people from 74 counties in 9 cities received anthelmintic medicine. The numbers receiving health education were 39 866 923 in county, 34,730,663 in city, 3,2000 in province, respectively. The coverage rate of non-hazardous sanitary latrines was 58.05%. In 2009, 6,581 people were surveyed from 7 counties or cities and the infection rate of soil-transmitted parasitic diseases was 7.61%. During three years, 30 provincial training classes were held and 2,130 people attended, 52 municipal classes were held and 3110 people attended, and 403 county classes were held and 12,789 people attended. In the whole province, the infection rate of soil-transmitted parasitic diseases reduced to 7.10% in 2009, with the reduction rate of 61.12%, reaching the national objective. CONCLUSIONS: The comprehensive control model for soil-transmitted parasitic diseases is very successful in Shandong Province.

Controllable fabrication of patterned ZnO nanorod arrays: investigations into the impacts on their morphology.

Fabricating ZnO nanorod arrays with precisely controlled morphology, alignment, and density is highly desirable but rather challenging. On the other hand, understanding the parameters that affect their final morphology and the growth mechanisms is significant to integrate such patterned ZnO nanorod arrays in various applications. Therefore, ZnO nanorod arrays with different density and morphology were fabricated by electron beam lithography (EBL) combined with the hydrothermal methods in this work. The influences of prepatterned geometry and the growth parameters such as seed layer, the precursor concentration, and the growth time on their final morphology were investigated. Under the coactions of EBL and the subsequent hydrothermal growth, ZnO nanorod arrays with precisely controlled density, position and morphology were achieved. The growth mechanism was also discussed in detail for the ZnO nanorod arrays which confined by the aperture with different size.

Inhibition of C35 gene expression by small interfering RNA induces apoptosis of breast cancer cells.

C35 was reported to be a new biomarker and therapeutic target for breast cancer. To explore the functional importance of C35, we constructed small interfering RNA (siRNA) targeting C35 and investigated the effects of the siRNAs on C35 expression and apoptosis of T47D cells. C35 siRNAs were constructed and named psiRNA-C35-1 and psiRNA-C35-2. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blots were used to detect the effects of the siRNAs on mRNA and protein expression of C35 in T47D cells. The effects of the two siRNAs on apoptosis of T47D cells were detected by flow cytometry and terminal dUTP nicked-end labelling assays. Also, the apoptosis related molecule caspase-3 was detected using Western blots. The psiRNA-C35-1 and psiRNA-C35-2 siRNAs were verified by both EcoR I/Hind III digestion analysis and automated DNA sequencing. RT-PCRs and Western blots showed that C35 mRNA and protein expression in T47D cells were obviously inhibited after psiRNA-C35-1 and psiRNA-C35-2 transfection. Flow cytometry and terminal dUTP nicked-end labelling assays showed that apoptosis of T47D cells was significantly induced after transfection with psiRNA-C35-1 and psiRNA-C35-2 (p < 0.05). Also, caspase-3 expression in the psiRNA-C35-1 and psiRNA-C35-2 transfected cells was obviously higher than that of the Lipofectamine and pTZU6+1 transfected cells. This study showed that apoptosis of T47D cells can be significantly induced by inhibiting C35 expression using siRNAs, which may be caused by activating caspase-3. C35 might play an important role in apoptosis of breast cancer cells, and therapeutic strategies targeting C35 may be useful for breast cancer treatment.

[Cloning and identification of ROP2 gene of Toxoplasma gondii].

OBJECTIVE: To amplify ROP2 from the genomic DNA of Toxoplasma gondii RH strain and construct eukaryotic expression plasmid pc-DNA3-ROP2. METHODS: Tachyzoites of T. gondii RH strain were collected and depurated to obtain genome. A pair of primers was designed and synthesized according ROP2 gene sequence. The gene fragment encoding ROP2 was amplified from the genomic DNA of T. gondii RH strain by means of PCR. It was then reclaimed and purified, and inserted into cloning vector pUCm-T. The recon was cut by EcoR I, Hind III, and the inserted ROP2 gene fragment was subcloned into pc-DNA3 eukaryotic expression vector using T4DNA ligase, followed by further PCR identification, double digestion via restrictive enzymes, and sequencing. RESULTS: The amplified specific gene fragment of ROP2 was about 1.7 kb in length. The gene fragment cloned and subcloned into pc-DNA3 was correct, and the eukaryotic expression plasmid contained ROP2 gene fragment was successfully constructed. CONCLUSION: The recombinant plasmid pc-DNA3-ROP2 was successfully constructed.

Biological role of surface Toxoplasma gondii antigen in development of vaccine.

AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii (T gondii) in development of vaccine. METHODS: The surface antigen of T gondii (SAG1) was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of T gondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on T gondii tachyzoites under electromicroscope. RESULTS: The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-gamma, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-alpha were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against T gondii may be regulated by both hormone- and cell-mediated immune response.