Antidepressant Augmentation versus Switch in Treatment-Resistant Geriatric Depression.

BACKGROUND: The benefits and risks of augmenting or switching antidepressants in older adults with treatment-resistant depression have not been extensively studied. METHODS: We conducted a two-step, open-label trial involving adults 60 years of age or older with treatment-resistant depression. In step 1, patients were randomly assigned in a 1:1:1 ratio to augmentation of existing antidepressant medication with aripiprazole, augmentation with bupropion, or a switch from existing antidepressant medication to bupropion. Patients who did not benefit from or were ineligible for step 1 were randomly assigned in step 2 in a 1:1 ratio to augmentation with lithium or a switch to nortriptyline. Each step lasted approximately 10 weeks. The primary outcome was the change from baseline in psychological well-being, assessed with the National Institutes of Health Toolbox Positive Affect and General Life Satisfaction subscales (population mean, 50; higher scores indicate greater well-being). A secondary outcome was remission of depression. RESULTS: In step 1, a total of 619 patients were enrolled; 211 were assigned to aripiprazole augmentation, 206 to bupropion augmentation, and 202 to a switch to bupropion. Well-being scores improved by 4.83 points, 4.33 points, and 2.04 points, respectively. The difference between the aripiprazole-augmentation group and the switch-to-bupropion group was 2.79 points (95% CI, 0.56 to 5.02; P = 0.014, with a prespecified threshold P value of 0.017); the between-group differences were not significant for aripiprazole augmentation versus bupropion augmentation or for bupropion augmentation versus a switch to bupropion. Remission occurred in 28.9% of patients in the aripiprazole-augmentation group, 28.2% in the bupropion-augmentation group, and 19.3% in the switch-to-bupropion group. The rate of falls was highest with bupropion augmentation. In step 2, a total of 248 patients were enrolled; 127 were assigned to lithium augmentation and 121 to a switch to nortriptyline. Well-being scores improved by 3.17 points and 2.18 points, respectively (difference, 0.99; 95% CI, -1.92 to 3.91). Remission occurred in 18.9% of patients in the lithium-augmentation group and 21.5% in the switch-to-nortriptyline group; rates of falling were similar in the two groups. CONCLUSIONS: In older adults with treatment-resistant depression, augmentation of existing antidepressants with aripiprazole improved well-being significantly more over 10 weeks than a switch to bupropion and was associated with a numerically higher incidence of remission. Among patients in whom augmentation or a switch to bupropion failed, changes in well-being and the occurrence of remission with lithium augmentation or a switch to nortriptyline were similar. (Funded by the Patient-Centered Outcomes Research Institute; OPTIMUM ClinicalTrials.gov number, NCT02960763.).

Human Papillomavirus-Associated Sexual Risks Among High School Students in the U.S.: Does Sexual Orientation Play a Role?

We examined the association between sexual orientation and human papillomavirus (HPV)-related risky sexual behaviors among high school students in the U.S. We used the 2015 Youth Risk Behavior Survey, a three-stage cluster sample, nationally representative, cross-sectional study. Participants were sexually active students (Grades 9-12) in public, private, and Catholic schools in 50 states and the District of Columbia (n = 5,958). Sexual orientation dimensions were: sexual self-identity (heterosexual, gay, lesbian, bisexual, and not sure) and sex of sexual contacts. HPV-associated risky sexual risk behaviors selected a priori were early sexual debut (≤ 12 or ≥ 13 years old) and number of lifetime partners (≥ 2 or ≥ 4). Separate multiple logistic regression analyses estimated association between sexual orientation and sex of sexual contacts, and HPV-associated risky sexual behaviors. Among the 5,958 high school students, a quarter had ≥ 4, and two-thirds had ≥ 2 sexual partners. Students who self-identified as bisexual (aOR = 2.43, 99% CI 1.19-4.98) or "not sure" (aOR = 4.56, 99% CI 2.54-8.17) were more likely to have sexual debut before 13 years. Similarly, students whose sexual contacts were adolescent females who had sex with females and males were more likely to have sexual debut before they turned 13 years of age (aOR = 3.46, 99% CI 1.83-6.48), or had ≥ 4 sexual partners (aOR = 2.66, 99% CI 1.74-4.08), or had ≥ 2 sexual partners (aOR = 3.09, 99% CI 1.91-5.00). In conclusion, HPV-associated risky sexual behavior is prevalent among high school students, especially sexual minorities. Interventions tailored to this population could increase HPV vaccine uptake and prevent future HPV-associated cancers and other negative outcomes.

Experiences of American Older Adults with Pre-existing Depression During the Beginnings of the COVID-19 Pandemic: A Multicity, Mixed-Methods Study.

OBJECTIVE: To determine the effect of the COVID-19 pandemic on the mental health of older adults with pre-existing major depressive disorder (MDD). PARTICIPANTS: Participants were 73 community-living older adults with pre-existing MDD (mean age 69 [SD 6]) in Los Angeles, New York, Pittsburgh, and St Louis. DESIGN AND MEASUREMENTS: During the first 2 months of the pandemic, the authors interviewed participants with a semistructured qualitative interview evaluating access to care, mental health, quality of life, and coping. The authors also assessed depression, anxiety, and suicidality with validated scales and compared scores before and during the pandemic. RESULTS: Five themes from the interviews highlight the experience of older adults with MDD: 1) They are more concerned about the risk of contracting the virus than the risks of isolation. 2) They exhibit resilience to the stress and isolation of physical distancing. 3) Most are not isolated socially, with virtual contact with friends and family. 4) Their quality of life is lower, and they worry their mental health will suffer with continued physical distancing. 5) They are outraged by an inadequate governmental response to the pandemic. Depression, anxiety, and suicidal ideation symptom scores did not differ from scores before the pandemic. CONCLUSION: Most older adults with pre-existing MDD show resilience in the first 2 months of the COVID-19 pandemic but have concerns about the future. Policies and interventions to provide access to medical services and opportunities for social interaction are needed to help to maintain mental health and quality of life as the pandemic continues.

Adsorption of Human Plasma Albumin and Fibronectin onto Nanostructured Black Silicon Surfaces.

The protein adsorption of two human plasma proteins-albumin (Alb) and fibronectin (Fn)-onto synthetic nanostructured bactericidal material-black silicon (bSi) surfaces (that contain an array of nanopillars) and silicon wafer (nonstructured) surfaces-was investigated. The adsorption behavior of Alb and Fn onto two types of substrata was studied using a combination of complementary analytical techniques. A two-step Alb adsorption mechanism onto the bSi surface has been proposed. At low bulk concentrations (below 40 µg/mL), the Alb preferentially adsorbed at the base of the nanopillars. At higher bulk concentrations, the Alb adsorbed on the top of the nanopillars. In the case of Fn, the protein preferentially adsorbed on the top of the nanopillars, irrespective of its bulk concentration.

Self-organised nanoarchitecture of titanium surfaces influences the attachment of Staphylococcus aureus and Pseudomonas aeruginosa bacteria.

The surface nanotopography and architecture of medical implant devices are important factors that can control the extent of bacterial attachment. The ability to prevent bacterial attachment substantially reduces the possibility of a patient receiving an implant contracting an implant-borne infection. We now demonstrated that two bacterial strains, Staphylococcus aureus and Pseudomonas aeruginosa, exhibited different attachment affinities towards two types of molecularly smooth titanium surfaces each possessing a different nanoarchitecture. It was found that the attachment of S. aureus cells was not restricted on surfaces that had an average roughness (S a) less than 0.5 nm. In contrast, P. aeruginosa cells were found to be unable to colonise surfaces possessing an average roughness below 1 nm, unless sharp nanoprotrusions of approximately 20 nm in size and spaced 35.0 nm apart were present. It is postulated that the enhanced attachment of P. aeruginosa onto the surfaces possessing these nanoprotrusions was facilitated by the ability of the cell membrane to stretch over the tips of the nanoprotrusions as confirmed through computer simulation, together with a concomitant increase in the level of extracellular polymeric substance (EPS) being produced by the bacterial cells.

Evaluation of Genetic and Nongenetic Risk Factors for Degenerative Cervical Myelopathy.

STUDY DESIGN: Cohort study. OBJECTIVE: We aimed to evaluate the associations of genetic and nongenetic factors with degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA: There is mounting evidence for an inherited predisposition for DCM, but uncertainty remains regarding specific genetic markers involved. Similarly, nongenetic factors are thought to play a role. MATERIALS AND METHODS: Using diagnosis codes from hospital records linked to the UK Biobank cohort, patients with cervical spondylosis were identified followed by the identification of a subset with DCM. Nongenetic variables evaluated included age, sex, race, Townsend deprivation index, body mass index, occupational demands, osteoporosis, and smoking. Genome-wide association analyses were conducted using logistic regression adjusted for age, sex, population principal components, and follow-up. RESULTS: A total of 851 DCM cases out of 2787 cervical spondylosis patients were identified. Several nongenetic factors were independently associated with DCM including age [odds ratio (OR)=1.11, 95% CI=1.01-1.21, P =0.024], male sex (OR=1.63, 95% CI=1.37-1.93, P <0.001), and relative socioeconomic deprivation (OR=1.03, 95% CI=1.00-1.06, P =0.030). Asian race was associated with lower DCM risk (OR=0.44, 95% CI=0.22-0.85, P =0.014). We did not identify genome-wide significant (≤5×10 -8 ) single-nucleotide polymorphisms (SNPs) associated with DCM. The strongest genome-wide signals were at SNP rs67256809 in the intergenic region of the genes LINC02582 and FBXO15 on chromosome 18 ( P =1.12×10 -7 ) and rs577081672 in the GTPBP1 gene on chromosome 22 ( P =2.9×10 -7 ). No SNPs reported in prior DCM studies were significant after adjusting for replication attempts. CONCLUSIONS: Increasing age, male sex, and relative socioeconomic deprivation were identified as independent risk factors for DCM, whereas Asian race was inversely associated. SNPs of potential interest were identified in GTPBP1 and an intergenic region on chromosome 18, but these associations did not reach genome-wide significance. Identification of genetic and nongenetic DCM susceptibility markers may guide understanding of DCM disease processes, inform risk, guide prevention and potentially inform surgical outcomes. LEVEL OF EVIDENCE: Prognostic level III.

Application of machine learning in screening for congenital heart diseases using fetal echocardiography.

There is a growing body of literature supporting the utilization of machine learning (ML) to improve diagnosis and prognosis tools of cardiovascular disease. The current study was to investigate the impact that the ML framework may have on the sensitivity of predicting the presence or absence of congenital heart disease (CHD) using fetal echocardiography. A comprehensive fetal echocardiogram including 2D cardiac chamber quantification, valvar assessments, assessment of great vessel morphology, and Doppler-derived blood flow interrogation was recorded. The postnatal echocardiogram was used to ascertain the diagnosis of CHD. A random forest (RF) algorithm with a nested tenfold cross-validation was used to train models for assessing the presence of CHD. The study population was derived from a database of 3910 singleton fetuses with maternal age of 28.8 ± 5.2 years and gestational age at the time of fetal echocardiography of 22.0 weeks (IQR 21-24). The proportion of CHD was 14.1% for the studied cohort confirmed by post-natal echocardiograms. Our proposed RF-based framework provided a sensitivity of 0.85, a specificity of 0.88, a positive predictive value of 0.55 and a negative predictive value of 0.97 to detect the CHD with the mean of mean ROC curves of 0.94 and the mean of mean PR curves of 0.84. Additionally, six first features, including cardiac axis, peak velocity of blood flow across the pulmonic valve, cardiothoracic ratio, pulmonary valvar annulus diameter, right ventricular end-diastolic diameter, and aortic valvar annulus diameter, are essential features that play crucial roles in adding more predictive values to the model in detecting patients with CHD. ML using RF can provide increased sensitivity in prenatal CHD screening with very good performance. The incorporation of ML algorithms into fetal echocardiography may further standardize the assessment for CHD.

Disparities in human papillomavirus (HPV) vaccine initiation and completion based on sexual orientation among women in the United States.

OBJECTIVES: We compared HPV vaccine initiation and completion of heterosexual with lesbian and bisexual (LB) women. METHODS: We aggregated National Health and Nutrition Examination Survey data from 2009 to 2016 for 3,017 women aged 18 to 34 y in the United States. HPV vaccine initiation was defined as reported receipt of ≥1 dose of the vaccine and completion as receipt of the three recommended doses. Weighted percentages and multivariable logistic regression models were used to examine differences in HPV vaccine initiation and completion between heterosexual and LB women. RESULTS: Approximately 12% of respondents self-identified as LB women. Overall, a higher percentage of respondents (26%) had initiated the HPV vaccine than completed the three vaccine doses (17%). In the bivariate analysis, LB women had higher initiation ([35% of LB women versus 25% heterosexual]; p = .0012) and completion rates ([24% of LB women versus 17% heterosexual]; p = .0052) than heterosexual women. After adjusting for covariates, compared to heterosexual women, LB women were 60% (aOR = 1.60, 95% CI: 1.16-2.19) more likely to initiate and 63% (aOR = 1.63, 95% CI: 1.12-2.37) more likely to complete the HPV vaccine. CONCLUSIONS: Although LB women had higher likelihood of HPV vaccine initiation and completion compared with heterosexual women, their HPV vaccine uptake was well below the Healthy People 2020 target (80%). Understanding differences in the drivers of vaccine uptake in the LB population may inform strategies that would further increase HPV vaccine uptake toward achieving the 80% completion target.

Augmenting Computerized Cognitive Training With Vortioxetine for Age-Related Cognitive Decline: A Randomized Controlled Trial.

OBJECTIVE: Age-related cognitive decline, the deterioration in functions such as memory and executive function, is faced by most older adults and affects function and quality of life. No approved treatments exist for age-related cognitive decline. Computerized cognitive training has been shown to provide consistent albeit modest improvements in cognitive function as measured by neuropsychological testing. Vortioxetine, an antidepressant medication, has putative procognitive and proneuroplastic properties and therefore may be able to augment cognitive training. In this placebo-controlled study, the authors tested the cognitive benefits of vortioxetine added to cognitive training for adults age 65 or older with age-related cognitive decline. METHODS: After a 2-week lead-in period of cognitive training, 100 participants were randomly assigned to receive either vortioxetine or placebo in addition to cognitive training for 26 weeks. The primary outcome measure was global cognitive performance, assessed by the NIH Toolbox Cognition Battery Fluid Cognition Composite. The secondary outcome measure was functional cognition, assessed by the UCSD Performance-Based Skills Assessment. All participants received motivational messaging and support from study staff to maximize adherence to the training. RESULTS: Participants who received vortioxetine with cognitive training showed a greater increase in global cognitive performance compared with those who received placebo with cognitive training. This separation was significant at week 12 but not at other assessment time points. Both groups showed improvement in the secondary outcome measure of functional cognition, with no significant difference between groups. CONCLUSIONS: Vortioxetine may be beneficial for age-related cognitive decline when combined with cognitive training. These findings provide new treatment directions for combating cognitive decline in older adults.

On the interaction between fluoxetine and lipid membranes: Effect of the lipid composition.

Molecular interaction between the antidepressant fluoxetine and lipid bilayers was investigated in order to provide insights into the drug's incorporation to lipid membranes. In particular, the effects of lipid's unsaturation degree and cholesterol content on the partitioning of fluoxetine into large unilamellar vesicles (LUVs) comprised of unsaturated 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and saturated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) were evaluated using second derivative spectrophotometry and Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). It was found that fluoxetine partitioned to a greater extent into the liquid-crystalline DOPC LUVs than into the solid-gel DPPC LUVs. The lipid physical state dependence of drug partitioning was verified by increasing the temperature in which the partition coefficient of fluoxetine significantly increased upon the change of the lipid phase from solid-gel to liquid-crystalline. The incorporation of 28mol% cholesterol into the LUVs exerted a significant influence on the drug partitioning into both DOPC and DPPC LUVs. The ATR-FTIR study revealed that fluoxetine perturbed the conformation of DOPC more strongly than that of DPPC due to the cis-double bonds in the lipid acyl chains. Fluoxetine possibly bound to the carbonyl moiety of the lipids through the hydrogen bonding formation while displaced some water molecules surrounding the PO2- regions of the lipid head groups. Cholesterol, however, could lessen the interaction between fluoxetine and the carbonyl groups of both DOPC and DPPC LUVs. These findings provided a better understanding of the role of lipid structure and cholesterol on the interaction between fluoxetine and lipid membranes, shedding more light into the drug's therapeutic action.

Role of topological scale in the differential fouling of Pseudomonas aeruginosa and Staphylococcus aureus bacterial cells on wrinkled gold-coated polystyrene surfaces.

Wrinkled patterns, which possess an extensive surface area over a limited planar space, can provide surface features ranging across the nano- and microscale that have become an engineering material with the flexibility to be tuneable for a number of technologies. Here, we investigate the surface parameters that influence the attachment response of two model bacteria (P. aeruginosa and S. aureus) to wrinkled gold-coated polystyrene surfaces having topologies at the nano- and microscale. Together with flat gold films as the controls, surface feature heights spanned 2 orders of magnitude (15 nm, 200 nm, and 1 micron). The surface wrinkle topology was shown through confocal laser scanning microscopic, atomic force microscopic and scanning electron microscopic image analyses to consist of air-water interfacial areas unavailable for bacterial attachment, which were also shown to be stable by time-lapsed contact angle measurements. Imposition of the nanoscale wrinkles reduced P. aeruginosa attachment to 57% and S. aureus attachment to 20% of their flat equivalent surfaces whereas wrinkles at the microscale further reduced these attachments to 7.5% and 14.5%, respectively. The density of attachments indicated an inherent species specific selectivity that changed with feature dimension, attributable to the scale of the air-water interfaces in contact with the bacterial cell. Parameters influencing static bacterial attachment were the total projected surface areas minus the air-water interface areas and the scale of these respective air-water interfaces (area distribution) with respect to the cell morphology. The range of these controlling parameters may provide new design principles for the evolving suite of physical anti-biofouling materials not reliant on biocidal agents under development.

Copolymers enhance selective bacterial community colonization for potential root zone applications.

Managing the impact of anthropogenic and climate induced stress on plant growth remains a challenge. Here we show that polymeric hydrogels, which maintain their hydrous state, can be designed to exploit functional interactions with soil microorganisms. This microbial enhancement may mitigate biotic and abiotic stresses limiting productivity. The presence of mannan chains within synthetic polyacrylic acid (PAA) enhanced the dynamics and selectivity of bacterial ingress in model microbial systems and soil microcosms. Pseudomonas fluorescens exhibiting high mannan binding adhesins showed higher ingress and localised microcolonies throughout the polymeric network. In contrast, ingress of Bacillus subtilis, lacking adhesins, was unaltered by mannan showing motility comparable to bulk liquids. Incubation within microcosms of an agricultural soil yielded hydrogel populations significantly increased from the corresponding soil. Bacterial diversity was markedly higher in mannan containing hydrogels compared to both control polymer and soil, indicating enhanced selectivity towards microbial families that contain plant beneficial species. Here we propose functional polymers applied to the potential root zone which can positively influence rhizobacteria colonization and potentially plant growth as a new approach to stress tolerance.

The effect of a high frequency electromagnetic field in the microwave range on red blood cells.

The effect of red blood cells (RBC) exposed to an 18 GHz electromagnetic field (EMF) was studied. The results of this study demonstrated for the first time that exposure of RBCs to 18 GHz EMF has the capacity to induce nanospheres uptake in RBCs. The uptake of nanospheres (loading efficiency 96% and 46% for 23.5 and 46.3 nm nanospheres respectively), their presence and locality were confirmed using three independent techniques, namely scanning electron microscopy, confocal laser scanning microscopy and transmission electron microscopy. It appeared that 23.5 nm nanospheres were translocated through the membrane into the cytosol, while the 46.3 nm-nanospheres were mostly translocated through the phospholipid-cholesterol bilayer, with only some of these nanospheres passing the 2D cytoskeleton network. The nanospheres uptake increased by up to 12% with increasing temperature from 33 to 37 °C. The TEM analysis revealed that the nanospheres were engulfed by the cell membrane itself, and then translocated into the cytosol. It is believed that EMF-induced rotating water dipoles caused disturbance of the membrane, initiating its deformation and result in an enhanced degree of membrane trafficking via a quasi-exocytosis process.

The Bioeffects Resulting from Prokaryotic Cells and Yeast Being Exposed to an 18 GHz Electromagnetic Field.

The mechanisms by which various biological effects are triggered by exposure to an electromagnetic field are not fully understood and have been the subject of debate. Here, the effects of exposing typical representatives of the major microbial taxa to an 18 GHz microwave electromagnetic field (EMF)were studied. It appeared that the EMF exposure induced cell permeabilisation in all of the bacteria and yeast studied, while the cells remained viable (94% throughout the exposure), independent of the differences in cell membrane fatty acid and phospholipid composition. The resulting cell permeabilisation was confirmed by detection of the uptake of propidium iodine and 23 nm fluorescent silica nanospheres using transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Upon EMF exposure, the bacterial cell membranes are believed to become permeable through quasi-endocytosis processes. The dosimetry analysis revealed that the EMF threshold level required to induce the uptake of the large (46 nm) nanopsheres was between three and six EMF doses, with a specific absorption rate (SAR) of 3 kW/kg and 5 kW/kg per exposure, respectively, depending on the bacterial taxa being studied. It is suggested that the taxonomic affiliation and lipid composition (e.g. the presence of phosphatidyl-glycerol and/or pentadecanoic fatty acid) may affect the extent of uptake of the large nanospheres (46 nm). Multiple 18 GHz EMF exposures over a one-hour period induced periodic anomalous increases in the cell growth behavior of two Staphylococcus aureus strains, namely ATCC 25923 and CIP 65.8T.

"Race for the Surface": Eukaryotic Cells Can Win.

With an aging population and the consequent increasing use of medical implants, managing the possible infections arising from implant surgery remains a global challenge. Here, we demonstrate for the first time that a precise nanotopology provides an effective intervention in bacterial cocolonization enabling the proliferation of eukaryotic cells on a substratum surface, preinfected by both live Gram-negative, Pseudomonas aeruginosa, and Gram-positive, Staphylococcus aureus, pathogenic bacteria. The topology of the model black silicon (bSi) substratum not only favors the proliferation of eukaryotic cells but is biocompatible, not triggering an inflammatory response in the host. The attachment behavior and development of filopodia when COS-7 fibroblast cells are placed in contact with the bSi surface are demonstrated in the dynamic study, which is based on the use of real-time sequential confocal imaging. Bactericidal nanotopology may enhance the prospect for further development of inherently responsive antibacterial nanomaterials for bionic applications such as prosthetics and implants.

Antibacterial titanium nano-patterned arrays inspired by dragonfly wings.

Titanium and its alloys remain the most popular choice as a medical implant material because of its desirable properties. The successful osseointegration of titanium implants is, however, adversely affected by the presence of bacterial biofilms that can form on the surface, and hence methods for preventing the formation of surface biofilms have been the subject of intensive research over the past few years. In this study, we report the response of bacteria and primary human fibroblasts to the antibacterial nanoarrays fabricated on titanium surfaces using a simple hydrothermal etching process. These fabricated titanium surfaces were shown to possess selective bactericidal activity, eliminating almost 50% of Pseudomonas aeruginosa cells and about 20% of the Staphylococcus aureus cells coming into contact with the surface. These nano-patterned surfaces were also shown to enhance the aligned attachment behavior and proliferation of primary human fibroblasts over 10 days of growth. These antibacterial surfaces, which are capable of exhibiting differential responses to bacterial and eukaryotic cells, represent surfaces that have excellent prospects for biomedical applications.

Perception of primary male sexual partners' characteristics and women's history of sexually transmissible infections in Ho Chi Minh City, Vietnam.

UNLABELLED: Background Evidence regarding whether male partners' characteristics can influence women's likelihood of getting sexually transmissible infections (STIs) is insufficient and inconsistent. Our study examined associations between women's perception of primary male partners' demographic and behavioural characteristics and women's history of bacterial STI diagnoses among 126 women at risk for STIs in Ho Chi Minh City, Vietnam. METHODS: All variables were obtained by women's self-report. Due to the excess zeroes of the number of bacterial STI diagnoses for women, we used Zero-Inflated Poisson regression to examine associations of interest. RESULTS: Among women who had one lifetime male partner (n=49), the partner's number of female sexual partners [prevalence ratio (PR)=4.63, 95%CI=1.44-14.88] and number of STI diagnoses (PR=27.32, 95%CI=1.56-477.70) were associated with the woman's number of bacterial STI diagnoses, after adjusting for women's education level. For women who had >1 lifetime male partner (n=77), a greater number of women's bacterial STI diagnoses was also associated with their partners' STI history (PR=9.12, 95% CI=2.44-34.11). CONCLUSIONS: An increased risk for STIs in women was associated with both individual characteristics and their primary male partner's behavioural risk factors. Therefore, primary male partners' risk factors should be included in STI risk assessments, treatment and interventions for women.

Graphene Induces Formation of Pores That Kill Spherical and Rod-Shaped Bacteria.

Pristine graphene, its derivatives, and composites have been widely reported to possess antibacterial properties. Most of the studies simulating the interaction between bacterial cell membranes and the surface of graphene have proposed that the graphene-induced bacterial cell death is caused either by (1) the insertion of blade-like graphene-based nanosheets or (2) the destructive extraction of lipid molecules by the presence of the lipophilic graphene. These simulation studies have, however, only take into account graphene-cell membrane interactions where the graphene is in a dispersed form. In this paper, we report the antimicrobial behavior of graphene sheet surfaces in an attempt to further advance the current knowledge pertaining to graphene cytotoxicity using both experimental and computer simulation approaches. Graphene nanofilms were fabricated to exhibit different edge lengths and different angles of orientation in the graphene sheets. These substrates were placed in contact with Pseudomonas aeruginosa and Staphylococcus aureus bacteria, where it was seen that these substrates exhibited variable bactericidal efficiency toward these two pathogenic bacteria. It was demonstrated that the density of the edges of the graphene was one of the principal parameters that contributed to the antibacterial behavior of the graphene nanosheet films. The study provides both experimental and theoretical evidence that the antibacterial behavior of graphene nanosheets arises from the formation of pores in the bacterial cell wall, causing a subsequent osmotic imbalance and cell death.

Three-dimensional reconstruction of surface nanoarchitecture from two-dimensional datasets.

The design of biomaterial surfaces relies heavily on the ability to accurately measure and visualize the three-dimensional surface nanoarchitecture of substrata. Here, we present a technique for producing three-dimensional surface models using displacement maps that are based on the data obtained from two-dimensional analyses. This technique is particularly useful when applied to scanning electron micrographs that have been calibrated using atomic force microscopy (AFM) roughness data. The evaluation of four different surface types, including thin titanium films, silicon wafers, polystyrene cell culture dishes and dragonfly wings confirmed that this technique is particularly effective for the visualization of conductive surfaces such as metallic titanium. The technique is particularly useful for visualizing surfaces that cannot be easily analyzed using AFM. The speed and ease with which electron micrographs can be recorded, combined with a relatively simple process for generating displacement maps, make this technique useful for the assessment of the surface topography of biomaterials.

Nanotopography as a trigger for the microscale, autogenous and passive lysis of erythrocytes.

Microscale devices are increasingly being developed for diagnostic analysis although conventional lysis as an initial step presents limitations due to its scale or complexity. Here, we detail the physical response of erythrocytes to the surface nanoarchitecture of black Si (bSi) and foreshadow their potential in microanalysis. The physical interaction brought about by the spatial convergence of the two topologies: (a) the nanopillar array present on the bSi and (b) the erythrocyte cytoskeleton present on the red blood cells (RBCs), provides spontaneous stress-induced cell deformation, rupture and passive lysis within an elapsed time of ∼3 min from immobilisation to rupture and without external chemical or mechanical intervention. The mechano-responsive bSi surface provides highly active yet autogenous RBC lysis and a prospect as a front-end platform technology in evolving micro-fluidic platforms for cellular analyses.