Pt,P-codoped carbon nitride nanoenzymes for fluorescence and colorimetric dual-mode detection of cholesterol.

Cholesterol is an important lipid compound found in a variety of foods, and its level in human blood is closely related to human health. Therefore, development of rapid and accurate POCT (point-of-care testing) methods for cholesterol detection is crucial for assessing food quality and early diagnosis of diseases, in particular, in a resource-limited environment. In this study, a smartphone-assisted colorimetric biosensor is constructed based on platinum,phosphorus-codoped carbon nitride (PtCNP2) for the rapid detection of cholesterol. Phosphorus-doped carbon nitride is prepared by thermal annealing of urea and NH4PF6, into which platinum is atomically dispersed by thermal refluxing. The obtained PtCNP2 exhibits an excellent peroxidase-like activity under physiological pH, whereby colorless o-phenylenediamine (OPD) is oxidized to colored 2,3-diaminophenazine (DAP) in the presence of hydrogen peroxide (H2O2), which can be produced during the oxidation of cholesterol by cholesterol oxidase. A smartphone-assisted visual sensing system is then constructed based on the color recognition software, and rapid on-site detection of cholesterol is achieved by reading the RGB values. Meanwhile, the generated DAP shows an apparent fluorescence signal and can realize highly sensitive detection of cholesterol by the change of the fluorescence signal intensity. Such a cholesterol sensor exhibits a wide linear detection range of 0.5-600 µg mL-1 and a low detection limit of 59 ng mL-1. The practicality of the sensor is successfully demonstrated in the rapid detection of cholesterol in serum and food.

Acupuncture Needle-Based Transistor Neuroprobe for In Vivo Monitoring of Neurotransmitter.

Chemical communication via neurotransmitters is central to brain functions. Nevertheless, in vivo real-time monitoring of neurotransmitters released in the brain, especially the electrochemically inactive molecules, remains a great challenge. In this work, a novel needle field-effect transistor (FET) microsensor based on an acupuncture needle is proposed, which is demonstrated to be capable of real-time monitoring dopamine molecules as well as neuropeptide Y in vivo. The FET microstructure is fabricated by successively wrapping an insulating layer and a gold layer on the top of the needle, where the needle and the Au served as the source and drain, respectively. After assembling reduced graphene oxide (RGO) between the source and drain electrodes, the specific aptamer is immobilized on the RGO, making this needle-FET biosensor highly selective and sensitive to real-time monitor neurotransmitters released from rat brain, even in a Parkinson's diseases model. Furthermore, the needle-FET biosensor is applied to detect a variety of targets including hormones, proteins, and nucleic acid. By constructing a FET sensing interface on an acupuncture needle and implanting the sensor in a rat's brain for in vivo detection, this work provides a new sight in the FET domain and further expands the species of real-time in vivo detection.

First Report of Pestalotiopsis lushanensis Causing Brown Leaf Spot on Sarcandra glabra in China.

Sarcandra glabra is a species of Chloranthaceae family and this family grow in the southern part of China, Japan, and Southeastern Asia (Li et al. 2019). It is a kind of precious Chinese herbal medicine, which occupies an important position in traditional Chinese herbal medicine. It plays an effective role in the treatment of cancer, rheumatism, pneumonia, digestive tract inflammations, traumatic injuries and fractures, anti-virus, anti-bacterial, antioxidant, etc. (Li et al. 2019; Zheng et al. 2003; Zhou et al. 2013). Since June 2020, we discovered a serious leaf disease in the S. glabra planting base of Shibing County (108.12E 27.03N), in Guizhou Province, with an incidence rate of 60% and yield losses of 40%. Initially, the symptoms developed as small specks where spots were purple with a dark brown halo margin, and round or oval. In later stages, the spots gradually expanded and became dry, whole severe leaf loss. To identify the pathogen, we collected the diseased leaves from S. glabra fields in Shibing County. Small tissue pieces from the edges of lesions were disinfected in 75% ethyl alcohol for 30 s and 1% hypochlorite for 1 min, rinsed five times in sterile water, plated on potato dextrose agar (PDA), and incubated at 28°C in lighted incubator for 3 days. Fungal colonies were consistently isolated and transferred to PDA for morphological characterization (Fang et al. 2007). Pathogenicity tests of the novel isolate HGUP CSH-2 were conducted by spraying spore suspensions with a concentration of 1.6×108 conidia/ml on surface-disinfected (70% ethyl alcohol, 30 s) leaves, while sterile distilled water was used as the control. Plants with inoculated leaves (three per treatment) were placed in lighted growth chambers at 28°C for 5 days and watered as needed (Light to dark ratio 1:1, RH=90%). Symptoms on inoculated leaves were similar to those described previously in the field. The same pathogenic fungus was re-isolated from the infected leaves but not from the non-inoculated leaves. Colonies on PDA attaining 70 mm diam after 7 d at 28°C, with pale honey-colored, sparse aerial mycelia on the surface with black, gregarious conidiomata. Conidiogenous cell discrete or integrated, ampulliform, clavate or subcylindrical, hyaline, smooth-walled, wide at base. Conidia fusoid, ellipsoid, straight to slightly curved, 4-septate, slightly constricted at septa, 22.26-27.17×6.9-8.22 µm (av.±SD: 24.68±1.57×7.68±0.38 µm; n=30). According to the colony and conidia characteristics, the isolate was initially identified as Pestalotiopsis spp. (Liu et al. 2017). The pathogen was confirmed by amplification and sequencing of the internal transcribed spacer region (ITS) gene, the translation elongation factor-1 (TEF1) gene and the ß-tubulin (TUB2) gene (Liu et al. 2017) using ITS1/ITS4, Bt2a/T1 and EF1-526F/1567R primers, respectively. The sequences of the PCR products were deposited in GenBank with accession numbers MT919215 (ITS), MT939300 (TUB2) and MT939299 (TEF1). BLAST results of the obtained sequences of the ITS, TUB2 and TEF1 genes revealed 97.16% (479/493 nucleotides), 99.56% (675/678 nucleotides) and 99.89% (890/891 nucleotides) homology with those of Pestalotiopsis lushanensis in GenBank (MG726538, KY464157 and KX895223). Maximum Likelihood method was used for phylogenetic analysis. The result showed that HGUP CSH-2 was together with P. lushanensis with a support rate of 100%. According to the morphological characteristics and molecular phylogenetic analysis, the pathogen was identified as P. lushanensis. So far as we know, our research is the first report of brown leaf spot of S. glabra caused by P. lushanensis in China. Thus, identification of P. lushanensis for this disease is important for the advancement of effective prevention and control practises as future perspectives.

Nanostructuring Synergetic Base-Stacking Effect: An Enhanced Versatile Sandwich Sensor Enables Ultrasensitive Detection of MicroRNAs in Blood.

MicroRNA (MiRNA)-based noninvasive diagnostics are hampered by the challenge in the quantification of circulating miRNAs using a general strategy. Here, we present a base-stacking effect-mediated ultrasensitive electrochemical miRNA sensor (BSee-miR) with a universal sandwich configuration. In the BSee-miR, a short DNA probe (10 nucleotides) self-assembled on a gold electrode surface could effectively capture the target miRNA synergizing with another sequence based on coaxial sandwich base-stacking, which rivals the fully complementary strength. Importantly, such a sandwich structure is flexible to incorporate signal amplification strategies (e.g., biotin-avidin) that are usually difficult to achieve in short sequence detection. Using this design, the BSee-miR achieves a broad dynamic range with a detection limit down to 7.5 fM. Furthermore, we found a high-curvature nanostructuring synergetic base-stacking effect that could improve the sensitivity of the BSee-miR by two orders of magnitude (79.3 aM). Our BSee-miR also has a single-base resolution to discriminate the highly homologous miRNAs. More importantly, this approach is universal and has been used to probe target miRNAs varying in sequences and secondary structures. Our ultrasensitive sensor could detect miRNA in cell lysates and human blood and distinguish cancer patients from normal individuals, promising a versatile tool to measure clinically relevant miRNAs for tumor diagnostics.

Hierarchical Nanostructuring Array Enhances Mid-Hybridization for Accurate Herbal Identification via ITS2 DNA Barcode.

It remains a technical challenge to accurately identify close species of herbal medicines, especially from adulterants, because of their highly identical phenotypes and chemical compositions. Here, we report a direct, sequencing-free, high-curvature nanostructuring-based electrochemical herb sensor (nanoE-herb sensor) to identify herbal species quickly and accurately using ITS2 barcodes. We engineer a nano-roughened carbon-supported gold nanostructuring array by photolithograph-free, one-step electrodeposition. The 3D fractal nanostructures exhibit a high deflection angle that largely enhances DNA hybridization efficiency, particularly for the midcomplementary hybridization, as compared to the 2D planar surface. More importantly, such a trans-scale array biointerface (including macroscale carbon and nanoscale gold branches) can overcome the detection barrier of slow diffusion of a long genomic sequence and inaccessibility of the sequestered variations in ITS2 secondary structures through the out-protruded 3D functional nanostructures. Our nanoE-herb sensor achieves a detection limit of 0.18 fM for the 64-mer fragment of saffron ITS2 barcode with midhybridization and shows superior specificity against even single-base mismatch. The sensor also precisely differentiates saffron from six other adulterants by directly detecting unpurified asymmetric PCR amplicons (∼500 bp) with ITS2 sequences, suggesting its great potential in the field identification of herbal medicinal species and pathogenic bacteria with specific DNA barcodes.

Molybdenum disulfide field-effect transistor biosensor for ultrasensitive detection of DNA by employing morpholino as probe.

This work reports on a molybdenum disulfide (MoS2) based field-effect transistor (FET) biosensor for ultrasensitive label-free detection of DNA via phosphorodiamidate morpholino oligos (PMO)-DNA hybridization. After the chip was fabricated and the sensing channel was modified with positive charges, the negatively charged MoS2 nanosheet was drop-casted onto the channel, enabling MoS2 to tightly bind to the sensing surface via electrostatic interactions. Meanwhile, DNA analogue, PMO, was immobilized on the MoS2 surface, and detection of PMO-DNA hybridization was conducted by the fabricated MoS2 FET biosensor. Due to the neutral character and high affinity of PMO, a limit of detection (LOD) down to 6 fM was obtained, which is lower than that of the previously reported MoS2 FET DNA biosensor based on DNA-DNA hybridization. In addition, the MoS2 FET biosensor also showed high sequence specificity capable of distinguishing the complementary DNA from one-base mismatched DNA, three-base mismatched DNA and noncomplementary DNA. Moreover, the unique FET biosensor was able to detect DNA in complex sample like serum, making the method potential in disease diagnostics.

Antibiotic-resistant Pseudomonas aeruginosa infection in patients with bronchiectasis: prevalence, risk factors and prognostic implications.

Background and aims: Pseudomonas aeruginosa (PA) is the most common pathogen in bronchiectasis and frequently develops resistance to multiple classes of antibiotics, but little is known about the clinical impacts of PA-resistant (PA-R) isolates on bronchiectasis. We, therefore, investigated the prevalence, risk factors and prognostic implications of PA-R isolates in hospitalized bronchiectasis patients. Patients and methods: Between June 2011 and July 2016, data from adult bronchiectasis patients isolated with PA at the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. PA was classified as PA-R in case antibiogram demonstrated resistance on at least one occasion. Results: Seven hundred forty-seven bronchiectasis patients were assessed. Of these, 147 (19.7%) had PA isolate in the sputum or bronchoscopic culture. PA-R and PA-sensitive accounted for 88 (59.9%) and 59 (31.1%) patients, respectively. In multivariate model, factors associated with PA-R isolate in bronchiectasis included prior exposure to antibiotics (odds ratio [OR] =6.18), three or more exacerbations in the previous year (OR =2.81), higher modified Medical Research Council dyspnea scores (OR =1.93) and greater radiologic severity (OR =1.15). During follow-up (median: 26 months; interquartile range: 6-59 months), 36 patients died, of whom 24 (66.7%) had PA-R isolate at baseline. However, PA-R isolate was not associated with greater all-cause mortality in bronchiectasis. Conclusion: PA-R infection is common among bronchiectasis patients, mainly determined by prior exposure to antibiotics, frequent exacerbations, more pronounced dyspnea and more severe radiologic involvement. However, PA-R isolate is not an independent risk factor for all-cause mortality in bronchiectasis.

A sensitive acupuncture needle microsensor for real-time monitoring of nitric oxide in acupoints of rats.

This study reports an acupuncture needle modified with an iron-porphyrin functionalized graphene composite (FGPC) for real-time monitoring of nitric oxide (NO) release in acupoints of rats. A gold film was first deposited to the needle surface to enhance the conductivity. The FGPC was prepared via hydrothermal synthesis, and subsequently applied to the tip surface of acupuncture needle by electrochemical deposition method. The functionalized needle enabled a specific and sensitive detection of NO based on the favorably catalytic properties of iron-porphyrin and the excellent conductivity of graphene. Amperometric data showed that the needle achieved not only a low detection limit down to 3.2 nM in PBS solution, but also a satisfactory selectivity. Interestingly, the functionalized needle could be inserted into the acupoints of rats for real-time monitoring of NO in vivo. It was found that a remarkable response to NO was respectively obtained in different acupoints when stimulated by L-arginine (L-Arg), revealing that the release of NO was detectable in acupoints. We expect this work would showcase the applications of acupuncture needle in detecting some important signaling molecules in vivo, and exploring the mechanism of acupuncture treatment.

In vivo Monitoring of Serotonin by Nanomaterial Functionalized Acupuncture Needle.

Acupuncture treatment is amazing but controversial. Up to now, the mechanism of treating diseases by acupuncture and moxibustion is still unclear, especially the occurrence of the molecular events in local acupoints. Herein, we report an extremely stable microsensor by modifying carbon nanotube (CNT) to the tip surface of acupuncture needle and applying this CNT-modified acupuncture needle for real time monitoring of serotonin (5-HT) in vivo. To stabilize CNT modification on the needle tip surface, poly(3,4-ethylenedioxythiophene)(PEDOT) was employed as glue water to stick CNT on the needle. The detection limit of the CNT-modified needle was found to be approximately 50 nM and 78 nM in the PBS and the cell medium, respectively. In addition, the needle showed good selectivity to some inflammatory mediators and some electroactive molecules. For the first time, the CNT-modified needle could be directly probed into rat body for real time monitoring of 5-HT in vivo, showing a great potential for better understanding the mechanism of acupuncture treatment.

Identification of Chinese Herbs Using a Sequencing-Free Nanostructured Electrochemical DNA Biosensor.

Due to the nearly identical phenotypes and chemical constituents, it is often very challenging to accurately differentiate diverse species of a Chinese herbal genus. Although technologies including DNA barcoding have been introduced to help address this problem, they are generally time-consuming and require expensive sequencing. Herein, we present a simple sequencing-free electrochemical biosensor, which enables easy differentiation between two closely related Fritillaria species. To improve its differentiation capability using trace amounts of DNA sample available from herbal extracts, a stepwise electrochemical deposition of reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) was adopted to engineer a synergistic nanostructured sensing interface. By using such a nanofeatured electrochemical DNA (E-DNA) biosensor, two Chinese herbal species of Fritillaria (F. thunbergii and F. cirrhosa) were successfully discriminated at the DNA level, because a fragment of 16-mer sequence at the spacer region of the 5S-rRNA only exists in F. thunbergii. This E-DNA sensor was capable of identifying the target sequence in the range from 100 fM to 10 nM, and a detection limit as low as 11.7 fM (S/N = 3) was obtained. Importantly, this sensor was applied to detect the unique fragment of the PCR products amplified from F. thunbergii and F. cirrhosa, respectively. We anticipate that such a direct, sequencing-free sensing mode will ultimately pave the way towards a new generation of herb-identification strategies.

Fabrication of Ultrasensitive Field-Effect Transistor DNA Biosensors by a Directional Transfer Technique Based on CVD-Grown Graphene.

Most graphene field-effect transistor (G-FET) biosensors are fabricated through a routine process, in which graphene is transferred onto a Si/SiO2 substrate and then devices are subsequently produced by micromanufacture processes. However, such a fabrication approach can introduce contamination onto the graphene surface during the lithographic process, resulting in interference for the subsequent biosensing. In this work, we have developed a novel directional transfer technique to fabricate G-FET biosensors based on chemical-vapor-deposition- (CVD-) grown single-layer graphene (SLG) and applied this biosensor for the sensitive detection of DNA. A FET device with six individual array sensors was first fabricated, and SLG obtained by the CVD-growth method was transferred onto the sensor surface in a directional manner. Afterward, peptide nucleic acid (PNA) was covalently immobilized on the graphene surface, and DNA detection was realized by applying specific target DNA to the PNA-functionalized G-FET biosensor. The developed G-FET biosensor was able to detect target DNA at concentrations as low as 10 fM, which is 1 order of magnitude lower than those reported in a previous work. In addition, the biosensor was capable of distinguishing the complementary DNA from one-base-mismatched DNA and noncomplementary DNA. The directional transfer technique for the fabrication of G-FET biosensors is simple, and the as-constructed G-FET DNA biosensor shows ultrasensitivity and high specificity, indicating its potential application in disease diagnostics as a point-of-care tool.

Preparation of Graphene-Modified Acupuncture Needle and Its Application in Detecting Neurotransmitters.

We report a unique nanosensing platform by combining modern nanotechnology with traditional acupuncture needle to prepare graphene-modified acupuncture needle (G-AN), and using it for sensitive detection of neurotransmitters via electrochemistry. An electrochemical deposition method was employed to deposit Au nanoparticles (AuNPs) on the tip surface of the traditional acupuncture needle, while the other part of the needle was coated with insulation paste. Subsequently, the G-AN was obtained by cyclic voltammetry reduction of a graphene oxide solution on the surface of the AuNPs. To investigate the sensing property of the G-AN, pH dependence was measured by recording the open circuit potential in the various pH buffer solutions ranging from 2.0 to 10.0. What's more, the G-AN was further used for detection of dopamine (DA) with a limit of detection of 0.24 µM. This novel G-AN exhibited a good sensitivity and selectivity, and could realize direct detection of DA in human serum.

Serotype-specific identification of Dengue virus by silicon nanowire array biosensor.

In this work, we demonstrated a silicon nanowire (SiNW) biosensing platform capable of simultaneously identifying different Dengue serotypes on a single sensing chip. Four peptide nucleic acids (PNAs), specific to each Dengue serotypes (DENV-1 to DENV-4), were spotted on different areas of the SiNW array surface, and the covalently immobilized PNA probes were then interacted with different Dengue serotypes target to establish the specificity of detection. Detection scheme is based on the changes in resistances due to accumulation of negative charges contributed by the hybridized DNA target. The results show that resistance changes only occur in regions where the Dengue target hybridizes with its complementary probe. What is more, a mixture of two different Dengue serotypes obtained from a one-step duplex RT-PCR was applied to the multiplex SiNW surface to validate SiNW capability to identify multiple Dengue serotypes on a single sensing platform. Through this study, we have established the multiplex SiNW biosensor as a promising device to detect multiple Dengue infections with high specificity.

Oxidized low-density lipoprotein and ß-glycerophosphate synergistically induce endothelial progenitor cell ossification.

AIM: To investigate the ability of ox-LDL to induce ossification of endothelial progenitor cells (EPCs) in vitro and explored whether oxidative stress, especially hypoxia inducible factor-1α (HIF-1α) and reactive oxygen species (ROS), participate in the ossific process. METHODS: Rat bone marrow-derived endothelial progenitor cells (BMEPCs) were cultured in endothelial growth medium supplemented with VEGF (40 ng/mL) and bFGF (10 ng/mL). The cells were treated with oxidized low-density lipoprotein (ox-LDL, 5 µg/mL) and/or ß-glycerophosphate (ß-GP, 10 mmol/L). Calcium content and Von Kossa staining were used as the measures of calcium deposition. Ossific gene expression was determined using RT-PCR. The expression of osteocalcin (OCN) was detected with immunofluorescence. Alkaline phosphatase (ALP) activity was analyzed using colorimetric assay. Intercellular reactive oxygen species (ROS) were measured with flow cytometry. RESULTS: BMEPCs exhibited a spindle-like shape. The percentage of cells that expressed the cell markers of EPCs CD34, CD133 and kinase insert domain-containing receptor (KDR) were 46.2%±5.8%, 23.5%±4.0% and 74.3%±8.8%, respectively. Among the total cells, 78.3%±4.2% were stained with endothelial-specific fluorescence. Treatment of BMEPCs with ox-LDL significantly promoted calcium deposition, which was further significantly enhanced by co-treatment with ß-GP. The same treatments significantly increased the gene expression of core-binding factor a-1 (cbfa-1) and OCN, while decreased the gene expression of osteoprotegerin (OPG). The treatments also significantly enhanced the activity of ALP, but did not affect the number of OCN(+) cells. Furthermore, the treatments significantly increased ROS and activated the hypoxia inducible factor-1α (HIF-1α). In all these effects, ox-LDL acted synergistically with ß-GP. CONCLUSION: Ox-LDL and ß-GP synergistically induce ossification of BMEPCs, in which an oxidizing mechanism is involved.

Silicon nanowire biosensor for ultrasensitive and label-free direct detection of miRNAs.

MicroRNA (miRNA), a large and growing class of 18-24-nucleotide long, noncoding RNA molecules in all known animal and plant genomes, is a key player in gene regulation. The functions of miRNA are yet to be understood with respect to how and where it is produced and the changes within an organism associated with variations in miRNA expression level. The expression profiles serve as molecular diagnostics for diseases and new targets in drug discovery. Consequently, highly sensitive and selective detection of miRNA is playing a significant role in understanding miRNA functions. Existing major methods of detecting miRNA are dependent on hybridization, in which a target miRNA molecule is hybridized to a complementary probe molecule. Recently developed detection methods introduce nanomaterials to the hybridized duplex to enhance the sensitivity. However, all of them are indirect, involving labeling or conjugating process. To overcome the above-mentioned issues, we have demonstrated a highly sensitive and label-free direct detection method for miRNA by using peptide nucleic acids (PNAs)-functionalized silicon nanowires (SiNWs) biosensor. The sensor is capable of detecting target miRNA as low as 1 fM (10(-15) M), as well as identifying fully matched versus mismatched miRNA sequences. More importantly, the SiNW biosensor enables miRNA detection in total RNA extracted from HeLa cells. The developed detection method shows potential applications in label-free, early detection of miRNA as a biomarker in cancer diagnostics with very high sensitivity and good specificity.

Morpholino-functionalized silicon nanowire biosensor for sequence-specific label-free detection of DNA.

We investigated Morpholino-functionalized silicon nanowires (SiNWs) as a novel gene chip platform for the sequence-specific label-free detection of DNA. Morpholino attachment and subsequent Morpholino-DNA hybridization on silicon surface was characterized by X-ray photoelectron spectroscopy and fluorescence microscopy. The resultant Morpholino-modified surfaces showed high specificity of recognition for DNA. Subsequently, by using the same protocol, the surface of the SiNW biosensor was functionalized with Morpholino, and this was used for label-free Morpholino-DNA hybridization detection. Real-time measurements of the Morpholino-functionalized SiNW biosensor exhibited a decrease in a time-dependent conductance when complementary and mutant DNA samples were added. Furthermore, identification of fully complementary versus mismatched DNA samples was carried out by the Morpholino-functionalized SiNW biosensor. We demonstrated that DNA detection using the Morpholino-functionalized SiNW biosensor could be carried out to the hundreds of femtomolar range. The Morpholino-functionalized SiNWs show a novel biosensor for label-free and direct detection of DNA with good selectivity, and a promising application in gene expression.

Reversal effect of Stephania tetrandra-containing Chinese herb formula SENL on multidrug resistance in lung cancer cell line SW1573/2R120.

This research is aimed on reversing multidrug resistance (MDR) of chemotherapy in lung cancer. According to our previous research, chemotherapeutic drugs resistance in lung cancer is mainly due to high expression of multidrug resistance-associated protein (MRP) gene and activation of caspases. The effect of stephania tetrandra-containing Chinese herbal formula, namely Supplement Energy and Nourish Lung (SENL), is effective in enhancing efficacy and reducing toxicity of chemotherapy in lung cancer. However, the underlying mechnism is largely unknown. To understand whether and how SENL herbs function on multidrug-resistance lung cancer cells, we treated a multidrug resistance lung cancer cell line, SW1573/2R120 with SENL herbs alone or together with a chemotherapeutic drug, Adriamycin (ADM). We observed that SENL herbs had a significant synergistic effect with ADM in inhibiting the growth of SW1573/2R120 cells. SENL alone and particularly together with ADM could significantly increase cell apoptotic death via mitochondria- and caspase-dependent pathway. Furthermore, we showed that SENL herbs could reverse drug resistance of lung cancer cells by decreasing MRP expression and increasing accumulation of intracellular ADM, which in turn increase the sensitivity of cancer cells to ADM. Taken together, the mechanism underlying reversal effect of drug resistance by SENL treatment was reported here and further systematical investigation on SENL herbs may lead to solve drug resistance in lung cancer chemotherapy.

Label-free electrical detection of cardiac biomarker with complementary metal-oxide semiconductor-compatible silicon nanowire sensor arrays.

Arrays of highly ordered silicon nanowire (SiNW) clusters are fabricated using complementary metal-oxide semiconductor (CMOS) field effect transistor-compatible technology, and the ultrasensitive, label-free, electrical detection of cardiac biomarker in real time using the array sensor is presented. The successful detection of human cardiac troponin-T (cTnT) has been demonstrated in an assay buffer solution of concentration down to 1 fg/mL, as well as in an undiluted human serum environment of concentration as low as 30 fg/mL. The high specificity, selectivity, and swift response time of the SiNWs to the presence of ultralow concentrations of a target protein in a biological analyte solution, even in the presence of a high total protein concentration, paves the way for the development of a medical diagnostic system for point-of-care application that is able to provide an early and accurate indication of cardiac cellular necrosis.

[Effect of acupuncture on target action of ligustrazine in treatment of toxic deafness induced by gentamicin in guinea pigs].

OBJECTIVE: To explore an effective method for treating Gentamicin-induced deafness and the mechanism. METHODS: Guinea pigs were randomly divided into 5 groups: normal control group (group A), model group (group B), Ligustrazine group (group C), acupuncture group (group D) and Ligustrazine plus acupuncture group (group E). The group C, D and E were treated respectively by simple Ligustrazine, simple acupuncture at "Tinggong" (SI 19), "Yifeng" (TE 17), and "Waiguan" (TE 5), and Ligustrazine plus acupuncture. Ten days later, the auditory brainstem response (ABR) thresholds for the wave III , apoptosis and expressions of Bcl-2 and Bax proteins in the organ of Corti of the guinea pig were detected. RESULTS: In the group E, the ABR threshold was significantly lower than that in the group C (P<0.05), and apoptotic cells, the expression of Bax protein and the ratio of Bax/Bcl-2 were lower than those in the group C and D in the organ of Corti, and Bcl-2 protein expression was increased. CONCLUSION: Acupuncture at "Tinggong" (SI 19), "Yifeng" (TE 17), and "Waiguan" (TE 5) has a certain target-synergistic action on Ligustrazine and can increase therapeutic effect of Ligustrazine on Gentamicin-induced deafness, which are possible related with the inhibition of apoptosis, down-regulation of Bax expression and up-regulation of Bcl-2 expression.

Highly sensitive measurements of PNA-DNA hybridization using oxide-etched silicon nanowire biosensors.

The highly sensitive and sequence-specific detection of single-stranded oligonucleotides using nonoxidized silicon nanowires (SiNWs) is demonstrated. To maximize device sensitivity, the surface of the SiNWs was functionalized with a densely packed organic monolayer via hydrosilylation, subsequently immobilized with peptide nucleic acid (PNA) capable of recognizing the label-free complementary target DNA. Because of the selective functionalization of the SiNWs, binding competition between the nanowire and the underlying oxide is avoided. Transmission electron microscopy was conducted to clearly differentiate the SiNW surface before and after removal of SiO(2). Fluorescence microscopy was used to further realize the selectivity of the oxide-etched chemistry on the SiNWs and sequence specificity of PNA-DNA hybridization. The concentration-dependent resistance change measurements upon hybridization of PNA-DNA show that detection limit down to 10fM can be obtained. The SiNW devices also reveal the capability of an obvious discrimination against mismatched sequences. Among several efforts being made to improve detection sensitivity, this work addresses one significant issue regarding surface functionalization which enables highly sensitive biomolecular sensing with SiNWs.