Differentiation of bacteria cell wall using Raman scattering enhanced by nanoparticle array

We have fabricated surface-enhanced Raman scattering (SERS) substrates based on arrays of silver nanoparticles grown on porous anodic alumina templates. Using this nanotechnology platform, label-free and high-speed detection of bacteria are achieved. SERS spectra of various bacteria including Staphylococcus Aureus (Gram-positive bacterium), Klebsiella Pneumoniae (Gram-negative bacterium), and Mycobacterium Smegmatis (Mycobacterium) were recorded. The highly reproducible SERS-based technological platform is capable of differentiating different kinds of bacteria by PCA, LDA, clustering analysis, and SVM methods, which provides promising opportunity for biosensing of clinical microbes.

n-ZnO/LaAlO3/p-Si heterojunction for visible-blind UV detection

A visible-blind UV photodetector (PD) using a double heterojunction of n-ZnO/LaAlO3 (LAO)/p-Si was demonstrated. Inserted LAO layers exhibit electrical insulating properties and serve as blocking layers for photoexcited electrons from p-Si to n-ZnO, leading to an enhanced rectification ratio and a visible-blind UV detectivity of the n-ZnO/LAO/p-Si PDs due to the high potential barrier between LAO and p-Si layers (~2.0 eV). These results support the use of n-ZnO/LAO/p-Si PDs in the visible-blind UV PDs in a visible-light environment.

Biodegradation of nicotine by newly isolated Pseudomonas sp. CS3 and its metabolites

AIMS

Isolation and characterization of nicotine-degrading bacteria with advantages suitable for the treatment of nicotine-contaminated water and soil and detection of their metabolites.

METHODS AND RESULTS

A novel nicotine-degrading bacterial strain was isolated from tobacco field soil. Based on morphological and physiochemical properties and sequence of 16S rDNA, the isolate was identified as Pseudomonas sp., designated as CS3. The optimal culture conditions of strain CS3 for nicotine degradation were 30°C and pH 7·0. However, the strain showed broad pH adaptability with high nicotine-degrading activity between pH 6·0 and 10·0. Strain CS3 could decompose nicotine nearly completely within 24 h in liquid culture (1000 mg L(-1) nicotine) or within 72 h in soil (1000-2500 mg kg(-1) nicotine) and could endure up to 4000 mg L(-1) nicotine in liquid media and 5000 mg kg(-1) nicotine in soil. Degradation tests in flask revealed that the strain had excellent stability and high degradation activity during the repetitive degradation processes. Additionally, three intermediates, 3-(3,4-dihydro-2H-pyrrol-5-yl) pyridine, 1-methyl-5-(3-pyridyl) pyrrolidine-2-ol and cotinine, were identified by GC/MS and NMR analyses.

CONCLUSIONS

The isolate CS3 showed outstanding nicotine-degrading characteristics such as high degradation efficiency, strong substrate endurance, broad pH adaptability, and stability and persistence in repetitive degradation processes and may serve as an excellent candidate for applications in the bioaugmentation process to treat nicotine-contaminated water and soil. Also, detection of nicotine metabolites suggests that strain CS3 might decompose nicotine via a unique nicotine-degradation pathway.

SIGNIFICANCE AND IMPACT OF THE STUDY

The advantage of applying the isolated strain lies in broad pH adaptability and stability and persistence in repetitive use, the properties previously less focused in other nicotine-degrading micro-organisms. The strain might decompose nicotine via a nicotine-degradation pathway different from those of other nicotine-utilizing Pseudomonas bacteria reported earlier, another highlight in this study.

A strong red-emitting carbazole based europium(III) complex excited by blue light

A novel 2-positional linked carbazole based β-diketone with methoxyl in the 7-position (EMOCTFBD), and its europium(III) ternary complex Eu(EMOCTFBD)(3)phen were synthesized via a dexterously designed indirect routine, where EMOCTFBD was 1-(9-ethyl-7-methoxyl-9H-carbazol-2-yl)-4,4,4-trifluorobutane-1,3-dione and phen was 1,10-phenanthroline. Eu(EMOCTFBD)(3)phen shows high thermal stability. The introduction of a methoxyl in the 7-position of the carbazole ring remarkably enhanced the excitation band intensity in the blue region, and the complex exhibited intense red emission under blue-light excitation. The lowest triplet state energy was measured and suggests the photoluminescence process as a ligand-sensitized luminescence process (antenna effect). A bright red-emitting diode was fabricated by coating the complex phosphor onto a ∼460 nm-emitting InGaN chip. All the results indicate that Eu(EMOCTFBD)(3)phen is an interesting red-emitting material excited by blue light, and therefore may be applied in many fields without UV radiation.

Crossover behavior in the hydrogen sensing mechanism for palladium ultrathin films

Palladium has been extensively studied as a material for hydrogen sensors because of the simplicity of its reversible resistance change when exposed to hydrogen gas. Various palladium films and nanostructures have been used, and different responses have been observed with these diverse morphologies. In some cases, such as with nanowires, the resistance will decrease, whereas in others, such as with thick films, the resistance will increase. Each of these mechanisms has been explored for several palladium structures, but the crossover between them has not been systematically investigated. Here we report on a study aimed at deciphering the nanostructure-property relationships of ultrathin palladium films used as hydrogen gas sensors. The crossover in these films is observed at a thickness of approximately 5 nm. Ramifications for future sensor developments are discussed.

More vaccine efficacy studies on the recombinant Bacille Calmette-Guerin co-expressing Ag85B, Mpt64 and Mtb8.4

The immunogenicity of the recombinant Bacille Calmette-Guerin: rBCG-Ag85B-Mpt64(190-198)-Mtb8.4 (rBCG-AMM) was evaluated in our previous study. This paper compares the protective efficacy of rBCG-AMM, rBCG-A which overexpresses Ag85B and BCG in C57BL/6 mice. There was no significant difference in proliferation characteristics among rBCG-AMM, rBCG-A and BCG. The growth characteristics of rBCG-AMM in host tissue were identical to control BCG, suggesting the improved protective efficacy was directly related to the expression of the Ag85B-Mpt64(190-198)-Mtb8.4 fusion protein. The protective experiment demonstrated that rBCG-AMM could confer similar or even better protective efficacy against Mycobacterium tuberculosis infection compared with BCG or rBCG-A as evaluated by bacterial organ loads, lung histopathology and net weight gain or loss. The results suggested that the recombinant BCG: rBCG-Ag85B-Mpt64(190-198)-Mtb8.4 is a potential vaccine candidate for further study.

Improvement of conversion efficiency for multi-junction solar cells by incorporation of Au nanoclusters

We studied the photoluminescence (PL) and photovoltaic current-voltage characteristics of the three-junction InGaP/InGaAs/Ge solar cells by depositing Au nanoclusters on the cell surface. The increases of the PL intensity and short-circuit current after incorporation of Au nanoclusters are evident. An increase of 15.3% in energy conversion efficiency (from 19.6 to 22.6%) is obtained for the three-junction solar cells in which Au nanoclusters have been incorporated. We suggest that the increased light trapping due to radiative scattering from Au nanoclusters is responsible for improving the performance of the three-junction solar cells.

Gene therapeutic treatment of pancreatic cancer based on injection of pcDNA3.1/CCK plasmid with xenogeneic homologous cholecystokinin

AIM

To study the therapeutic effect of recombinant plasmid pcDNA3.1/CCK containing porcine gene of cholecystokinin (CCK).

METHODS

The confirmed fragments of porcine CCK cDNA were cloned into the pcDNA3.1 vector. Recombinant plasmid pcDNA3.1/CCK was injected into the muscles of Syrian golden hamsters. Before gene transfer, orthotopic tumor model and liver metastasis model of hamster pancreatic cancer have been established by injection of 1 x 10(6) PGHAM-1 cells into the pancreas and spleen of golden hamsters. Then the CCK expression in vivo and the tumor inhibiting effect were analyzed.

RESULTS

Our data revealed that recombinant plasmid pcDNA3.1/CCK had long-term expression in hamsters and induced generation of specific antibody. Antibody level correlated with the number of inoculations. Compared to the control, significant reduction in tumor volume, decrease in number of liver metastasis and a remarkable enhancement of survival rate were detected.

CONCLUSION

Intramuscular injection of recombinant plasmid pcDNA3.1/CCK has significant antitumor and antimetastatic effect in vivo.

Antibody response to four secretory proteins from Mycobacterium tuberculosis and their complex antigen in TB patients

OBJECTIVE

To evaluate antibody responses to a panel of four protein antigens secreted from Mycobacterium tuberculosis, CFP-21, ESAT-6, MPT-63 and MPT-64, and their complex antigen.

DESIGN

Seventy-eight samples of serum and cerebral spinal fluid were tested by ELISA.

RESULTS

Serum IgM antibody positive rates of protein antigens CFP-21, ESAT-6, MPT-63 and MPT-64 and their multi-antigen complex were respectively 34.6%, 60.3%, 52.6%, 78.2% and 96.2%; IgG antibody positive rates were respectively 46.2%, 64.1%, 93.6%, 57.7% and 84.6%. The specificity of the antibodies to the four proteins secreted from M. tuberculosis and its mixture antigen was 100%; sensitivity to the multi-antigen complex was higher than for the four single antigens. Among the IgM positive rates, the differences between the multi-antigen complex and CFP-21, ESAT-6, MPT-63 and MPT-64 were significant (P < 0.01); among the IgG positive rates, the differences between the multi-antigen complex and CFP-21, ESAT-6 and MPT-64 were significant (P < 0.01). Although the IgG positive rate for MPT-63 was higher than for the multi-antigen complex, the difference was not significantly different (P > 0.05).

CONCLUSION

These findings indicate that the multi-antigen complex composed of CFP-21, ESAT-6, MPT-63 and MPT-64 may be useful in the diagnosis of TB.

A real-time polymerase chain reaction-based method for rapid and specific detection of spoilage Alicyclobacillus spp. in apple juice

AIMS

To develop a real-time PCR-based rapid detection method for spoilage Alicyclobacillus spp. in juice products.

METHODS AND RESULTS

The squalene-hopene cyclase-encoding gene was targeted for primer-and-probe development. Gene fragments from representative strains were cloned, and PCR primers and probe were designed by DNA sequence comparison. Selected bacteria were examined for cross-reactivity by the new method. Cells were serially diluted in apple juice and saline, and examined by the new method to establish detection sensitivity. Using the newly developed Taqman real-time PCR-based method, strains of Alicyclobacillus acidocaldarius and A. acidoterrestris were detected without cross reactivity with other common food-borne micro-organisms. Detection of <10 cells per PCR reaction from juice samples was accomplished within 3-5 h.

CONCLUSION

This is the first reported real-time PCR-based detection method for Alicyclobacillus spp. and its application in juice products is demonstrated.

SIGNIFICANCE AND IMPACT OF THE STUDY

As a favourable alternative for the laborious and time-consuming culture- or biochemical characterization-based techniques, the system has great potential for industrial applications from raw material screening to final product quality control.

Assessment of solid state fermentation by a biolectronic artificial nose

The use of a bioelectronic artificial nose (AN) is described for on-site-monitoring to assess the reaction patterns of solid state fermentations for control of microclimate at sampling site. The nose consists of fractionated olfactory cell proteins of bullfrog (as a receptor membrane) coated on a piezoelectric quartz crystal connected to an oscillator and a data recorder with a personal computer (PC). Five fractions of the olfactory cell proteins gave 5 probes. The response of the nose was analyzed by the PC either as profiles to show the kinds of doors, or as scale factors to show the intensity of odours. Definite differences were noted between the profiles of the headspace gases from earlier and later stages of composing of solid hog wastes. The scale factors showed a single large peak in the earlier stage and one small peak in the later stage. The former showed vigorous biodegradation of organic matter and the latter indicated stabilization of the finished compost. In addition to its use in composing, the nose can discriminate various kinds of alcoholic beverages.

In vitro activities of small peptides from snake venom against clinical isolates of drug-resistant Mycobacterium tuberculosis

The recent re-emergence of tuberculosis, especially the multidrug-resistant cases, has highlighted the importance of screening effective novel drugs against Mycobacterium tuberculosis. In this study, the in vitro activities of small peptides isolated from snake venom were investigated against multidrug-resistant M. tuberculosis. Minimum inhibitory concentrations (MICs) were determined by the Bactec TB-460 radiometric method. A small peptide with the amino acid sequence ECYRKSDIVTCEPWQKFCYREVTFFPNHPVYLSGCASECTETNSKWCCTTDKCNRARGG (designated as vgf-1) from Naja atra (isolated from Yunnan province of China) venom had in vitro activity against clinically isolated multidrug-resistant strains of M. tuberculosis. The MIC was 8.5 mg/l. The antimycobacterial domain of this 60aa peptide is under investigation.

Assignment of the Raman spectra of some deuterated-BEDT-TTF superconductors

We present the room-temperature Raman spectra of both the protonated and deuterated forms of kappa-(BEDT-TTF)2Cu[N(CN)2]Br, kappa-(BEDT-TTF)2Cu(NCS)2 and beta-(BEDT-TTF)2I3. Along with data for the neutral BEDT-TTF molecule these spectra are used to assign the many features in the spectra of the deuterated compounds.

Regulation of B16F1 melanoma cell metastasis by inducible functions of the hepatic microvasculature

We have previously shown that circulating intravascular cells generally arrest by mechanical restriction in the hepatic sinusoids, causing rapid release of nitric oxide (NO) which is cytotoxic to these cells and inhibits their growth into metastatic tumours. Here, we present evidence that these NO-dependent cytotoxic mechanisms are susceptible to upregulation by lipopolysaccharide (LPS). Five x 10(5) fluorescently labelled melanoma cells were injected into the mesenteric vein of C57BL/6 mice to effect their localisation in the hepatic microvasculature. Test mice were then given 1 mg/kg LPS intraperitoneally (i.p.) to activate the microvascular cells. By electron paramagnetic resonance (EPR) spectroscopy, the expression of NO in the liver was significantly increased by 8 h in the LPS-treated mice. The non-selective NO synthase inhibitor L-NAME inhibited the induction of NO by LPS, while its inactive enantiomer D-NAME had no significant effect. Using immunohistochemistry (IHC), iNOS-positive microvascular cells were detected in the terminal portal venule (TPV) region of the liver 8 h after LPS stimulation. LPS treatment also increased the retention of melanoma cells in the liver between 8 and 24 h, especially in the TPV region. Eight hours after cell injection, local expression of VCAM-1 and ICAM-1 was detected by double-label immunohistochemistry at the sites of tumour cell arrest. Expression of these adhesion molecules was enhanced in mice treated with LPS. Using flow cytometry, 98% of the B16F1 melanoma cells expressed VLA-4, the counter receptor of VCAM-1, and approximately 1.5% expressed LFA-1, the counter receptor of ICAM-1. LPS did not significantly alter the expression of either counter receptor on melanoma cells in vitro or in vivo. By DNA end-labelling, the rates of melanoma cell apoptosis were significantly increased from 8 to 24 h in the TPV region (but not in the sinusoids) of LPS-treated mice. Fourteen days after tumour cell injection, the LPS-treated mice had a significantly smaller hepatic metastatic tumour burden than the control mice. These data suggest that LPS can inhibit the metastasis of melanoma cells in the liver by inducing the expression of NO and adhesion molecules by the hepatic endothelium. The induction of iNOS and the inducible cytotoxic effect of LPS appear to be primarily located within the TPV region of the liver acinus.

Shear stress-induced nitric oxide release triggers the liver regeneration cascade

The trigger of the liver regeneration cascade is currently unknown and has been the subject of debate. We hypothesize that, following 2/3 partial hepatectomy (PHX), an increase in the blood flow-to-liver mass ratio results in shear stress-induced nitric oxide (NO) release, which triggers the liver regeneration cascade. Portal venous pressure (PVP), reflecting shear stress in the liver, increased to the same extent following PHX and selective portal vein branch ligation (PVL), a hemodynamic model of PHX, suggesting similar amounts of shear stress in both models. Two indices of the initiation of the liver regeneration cascade were used: proliferative factor (PF) activity in blood 4 h after PHX or PVL and hepatic c-fos mRNA expression 15 min. after PHX or PVL. PF activity and c-fos mRNA expression were increased to similar extents after PHX and PVL, suggesting a similar stimulus in both models. PF activity and c-fos mRNA expression were inhibited by administration of the nitric oxide synthase antagonist, l-NAME, and the NO donor, SIN-1, reversed the inhibition in both models. These results provide support for the hypothesis that a hemodynamic change results in increased shear stress in the liver causing generation of NO, which then triggers the liver regeneration cascade.

A Comparison of Two Models of Health‐Promoting Lifestyle in Rural Elderly Taiwanese Women

The purposes of this study were to: (1) examine the relations among age, marital status, social class, perceived health, self-care agency, health-promoting lifestyle, and well-being in two groups of rural elderly Taiwanese women and (2) validate and compare two models using the two age groups of rural elderly Taiwanese women. Based on the conceptualizations of the major study variables in Orem's self-care model (1995), Pender's health promotion model (1987), and other scholars' ideas (Hartweg, 1990; Simmons, 1990), a theoretical model of health-promoting lifestyle was proposed for this study. A survey-interview method was used for data collection. Two groups of elderly women were recruited for data analysis: 168 in the younger group and 116 in the older group. The mean age was 64.66 in the younger group and 75.59 in the older group. Two models of health-promoting lifestyle were tested with a path analysis, using the Linear Structural Relations 8 (LISREL 8) program. The resultant models yielded chi2 of 13.69 with 9 degrees of freedom (p = 0.13) in the younger group and chi2 of 15.76 with 10 degrees of freedom (p = 0.11) in the older group. Other fit indices also indicate the two models fit the data well. Community nurses can assess, identify, and use effective interventions for rural elderly women on a basis of the resulting models.

Analytical models of atherosclerosis

Atherosclerosis is responsible for approximately 50% of all mortalities in the USA, Europe, and Japan. An innovative approach for investigating atherosclerotic lesions using a thermodynamic model and a boundary value model and an analytical example of a human abdominal aorta vessel with an initial lesion are presented in the paper. Analytical results given by both models propose that increased transient boundary layer thickness and reduced surface energy of adhesion in regions of the arterial branch points play crucial roles in initial lesion formation. This study also improves the understanding of atherosclerotic mechanisms and helps to interpret clinical and experimental results.

Using a focus group study to explore perceptions of health-promoting self-care in community-dwelling older adults

The purpose of this study was to explore perceptions of health-promoting self-care in community-dwelling older adults. A focus group was conducted to obtain the perceptions and experiences of older adults concerning health-promoting self-care in their daily lives. Twenty-one volunteers from a Golden-Age Association in Kaohsiung City, including 10 males and 11 females, agreed to participate in this study. The mean age of the participants was 73.5 years, with ages ranging from 67 to 83. Three focus group sessions were held and 21 participants participated in all three sessions. Each focus group session lasted from 2.5 to 3 hours. The sessions were audio tape recorded and then verbatim transcripts were used for content analysis. Through a peer discussion, 51 behavioral units were extracted and categorized as five major themes including "balancing", "initiating", "regularizing", "socializing", and "sublimating". The findings can contribute to basic nursing knowledge related to health-promoting self-care and provide the basis for designing nursing strategies to enhance health-promoting self-care for older adults in the community.

What do we know about maternal-fetal attachment?

A review of the literature suggests that there are three critical attributes related to the concept of maternal-fetal attachment, including cognitive, affective, and altruistic attachment. Cognitive attachment is the desire to know the baby. Affective attachment is the pleasure associated with thoughts of or interaction with the fetus. Altruistic attachment refers to a desire to protect the unborn child. Existing measurements on maternal-fetal attachment are developed based on low-risk and white pregnant women and previous research has not yet resulted in a consistent theoretical model. Future research should focus on development of culturally sensitive instruments and combining qualitative and quantitative measures to broaden theoretical understanding of the concept. Nursing assessment of maternal-fetal attachment is an on-going process. The nurse's role is to reassure those who have developed attachment to their fetuses and to motivate those who are unaware of or unconcerned about their attachment to their fetuses. Collecting data from different attributes of attachment helps nurses identify each woman's attachment patterns and areas of concern.

Morphologic predictors of papillary carcinoma on fine-needle aspiration of thyroid with ThinPrep preparations

Although the cytologic features of papillary carcinoma of the thyroid are well-known, none is entirely specific. We conducted this study to determine the minimal criteria necessary to achieve 100% specificity for the diagnosis of papillary carcinoma on fine-needle aspiration (FNA). Forty patients with histologically confirmed papillary carcinoma and 17 patients with other thyroid lesions who underwent preoperative FNA at Beth Israel Deaconess Medical Center during a 4-yr period were included in the study. All cytology slides were prepared with the ThinPrep processing technique. Various architectural and nuclear features were evaluated, with a score assigned to each feature, and correlated with the histologic diagnosis of papillary carcinoma. Intranuclear inclusions, papillary and/or sheet arrangements, nuclear grooves, powdery chromatin, nuclear molding, high cellularity, and small nucleoli were significantly associated with papillary carcinoma (P < 0.05). The requirement of any intranuclear inclusions and many nuclear grooves, or a minimum of sum of scores (of the above eight features) of 10, yields 100% specificity and approximately 70% sensitivity. Cases with fewer features can be reported as suspicious or indeterminate for papillary carcinoma. A quantitative/probabilistic approach in the reporting of thyroid FNA provides a practical guide for management of patients with thyroid nodules.

Concept analysis of well-being

Traditionally, mortality and morbidity were considered two important indicators of health outcome. Until recently, the measurement of health outcome focused on individuals' subjective perceptions of well-being. Well-being has been popularly used in many scientific disciplines. The definitions of well-being, however, were diverse and inconsistent in previous literature. The ambiguous concept used in research study will impede the development of knowledge and theory. Concept analysis, therefore, is necessary to synthesize the existing views of well-being and distinguish it from other concepts to explicate the meaning of well-being.

Phenotypic characteristics of a distinctive multilayered epithelium suggests that it is a precursor in the development of Barrett's esophagus

A distinctive type of multilayered epithelium (ME) has been described at the neo-squamocolumnar junction and within columnar mucosa in patients with Barrett's esophagus (BE). This epithelium has morphologic and ultrastructural features of both squamous and columnar epithelium. Multilayered epithelium may represent an early or intermediate stage of columnar metaplasia; therefore, we performed this study to determine the morphologic and biologic characteristics of this epithelium and to gain insight into its derivation. Esophageal mucosal biopsies containing ME from 17 patients with BE were evaluated morphologically, stained with a variety of mucin histochemical stains; and also immunostained with antibodies against cytokeratins (CK) 13 (squamous epithelium marker); 14 (basal squamous epithelium marker) 7, 8/18, 19, and 20 (columnar epithelium markers), MIB-1 (proliferation marker); villin (intestinal brush border protein); and TGFalpha, EGFR, pS2, and hSP (enteric proliferation/differentiation regulatory peptides). The results were compared with normal esophageal squamous epithelium, normal gastric cardia epithelium, specialized-type intestinal epithelium (BE), and esophageal mucosal and submucosal gland duct epithelium. Multilayered epithelium expressed a pattern of mucin production (neutral mucin, sialomucin, and sulfomucin in 88%, 100%, and 71% of cases, respectively) and cytokeratin expression (CK 13 and 19 in the basal "squamoid" cells, CK 7, 8/18, 19, and 20 in the superficial "columnar" cells) similar to that of columnar epithelium in BE, and showed a high capacity for cellular proliferation (Ki-67-positive in 88% of cases) and differentiation (TGFalpha, EGFR, pS2 and villin-positive in 100%, 100%, 93%, and 66% of cases, respectively). The mucosal gland duct epithelium showed a similar phenotypic pattern and, in one case, was seen to give rise to ME at the surface of the mucosa. These data provide evidence in support of the hypothesis that ME represents an early or intermediate stage in the development of esophageal columnar metaplasia (BE). The mucosal gland duct epithelium may contain progenitor cells that can give rise to ME.