Stacking architecture for collimated backlight using cylindrical lens sheet with linear light sources or edge-lit/direct-lit BLU.

Highly collimated and directional backlights are essential for realizing advanced display technologies such as autostereoscopic 3D displays. Previously reported collimated backlights, either edge-lit or direct-lit, in general still suffer unsatisfactory form factors, directivity, uniformity, or crosstalk etc. In this work, we report a simple stacking architecture for the highly collimated and uniform backlights, by combining linear light source arrays and carefully designed cylindrical lens arrays. Experiments were conducted to validate the design and simulation, using the conventional edge-lit backlight or the direct-lit mini-LED (mLED) arrays as light sources, the NiFe (stainless steel) barrier sheets, and cylindrical lens arrays fabricated by molding. Highly collimated backlights with small angular divergence of ±1.45°âˆ¼±2.61°, decent uniformity of 93-96%, and minimal larger-angle sidelobes in emission patterns were achieved with controlled divergence of the light source and optimization of lens designs. The architecture reported here provides a convenient way to convert available backlight sources into a highly collimated backlight, and the use of optically reflective barrier also helps recycle light energy and enhance the luminance. The results of this work are believed to provide a facile approach for display technologies requiring highly collimated backlights.

Significant Changes of Corneal Astigmatism After Levator Muscle Surgery for Acquired Blepharoptosis.

PURPOSE: To investigate the change of corneal astigmatism after the correction of blepharoptosis. METHODS: This was a single-center retrospective cohort study conducted in Taiwan from 2017 to 2021. The medical records of patients with acquired blepharoptosis who had received levator muscle surgeries were collected. The differences in corneal astigmatism between the measurements before and at least 1 month after surgeries were investigated. Subgroup analysis of various severities of blepharoptosis and different types of corneal astigmatism was performed to determine their impacts on the axial changes after blepharoptosis surgeries. RESULTS: A total of 120 eyes of 68 patients were enrolled in this study. The mean axial change of corneal astigmatism was 17.4° after blepharoptosis surgeries, and 55 eyes (45.8%) had a change of at least 10°. In the subgroup analysis, the eyes with against-the-rule, with-the-rule, and oblique astigmatism had 42.9%, 68.4%, and 91.7% with an axial change of at least 10° after surgeries, respectively. The averaged axial change of corneal astigmatism after surgeries was 22.7° in eyes with severe blepharoptosis (margin to reflex distance1 < 1 mm), whereas it was 12.0° in eyes with mild-to-moderate blepharoptosis (margin to reflex distance1 ≥ 1 mm). CONCLUSIONS: A high proportion of eyes had a crucial axial change in corneal astigmatism after blepharoptosis surgeries, especially in those with oblique astigmatism and severe blepharoptosis. For blepharoptosis patients needing refractive surgeries or astigmatism correction with toric intraocular lens implantation, a surgical correction of blepharoptosis may be considered beforehand.

Health assessment of emerging persistent organic pollutants (POPs) in PM2.5 in northern and central Taiwan.

Over the last two decades, Taiwan has effectively diminished atmospheric concentrations of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) through the adept utilization of advanced technologies and the implementation of air pollution control devices. Despite this success, there exists a dearth of data regarding the levels of other PM2.5-bound organic pollutants and their associated health risks. To address this gap, our study comprehensively investigates the spatial and seasonal variations, potential sources, and health risks of PCDD/Fs, Polychlorinated biphenyls (PCBs), and Polychlorinated naphthalene (PCNs) in Northern and Central Taiwan. Sampling collections were conducted at three specific locations, including six municipal waste incinerators in Northern Taiwan, as well as a traffic and an industrial site in Central Taiwan. As a result, the highest mean values of PM2.5 (20.3-39.6 µg/m3) were observed at traffic sites, followed by industrial sites (14.4-39.3 µg/m3), and the vicinity of the municipal waste incinerator (12.4-29.4 µg/m3). Additionally, PCDD/Fs and PCBs exhibited discernible seasonal fluctuations, displaying higher concentrations in winter (7.53-11.9 and 0.09-0.12 fg I-TEQWHO/m3) and spring (7.02-13.7 and 0.11-0.16 fg I-TEQWHO/m3) compared to summer and autumn. Conversely, PCNs displayed no significant seasonal variations, with peak values observed in winter (0.05-0.10 fg I-TEQWHO/m3) and spring (0.03-0.08 fg I-TEQWHO/m3). Utilizing a Positive Matrix Factorization (PMF) model, sintering plants emerged as the predominant contributors to PCDD/Fs, constituting 77.9% of emissions. Woodchip boilers (68.3%) and municipal waste incinerators (21.0%) were identified as primary contributors to PCBs, while municipal waste incinerators (64.6%) along with a secondary copper and a copper sludge smelter (22.1%) were the principal sources of PCNs. Moreover, the study specified that individuals aged 19-70 in Northern Taiwan and those under the age of 12 years in Central Taiwan were found to have a significantly higher cancer risk, with values ranging from 9.26 x 10-9-1.12 x 10-7 and from 2.50 x 10-8-2.08 x 10-7respectively.

Interdependent progression of bidirectional sister replisomes in E. coli.

Bidirectional DNA replication complexes initiated from the same origin remain colocalized in a factory configuration for part or all their lifetimes. However, there is little evidence that sister replisomes are functionally interdependent, and the consequence of factory replication is unknown. Here, we investigated the functional relationship between sister replisomes in Escherichia coli, which naturally exhibits both factory and solitary configurations in the same replication cycle. Using an inducible transcription factor roadblocking system, we found that blocking one replisome caused a significant decrease in overall progression and velocity of the sister replisome. Remarkably, progression was impaired only if the block occurred while sister replisomes were still in a factory configuration - blocking one fork had no significant effect on the other replisome when sister replisomes were physically separate. Disruption of factory replication also led to increased fork stalling and requirement of fork restart mechanisms. These results suggest that physical association between sister replisomes is important for establishing an efficient and uninterrupted replication program. We discuss the implications of our findings on mechanisms of replication factory structure and function, and cellular strategies of replicating problematic DNA such as highly transcribed segments.

Long-Term Outcome of Treatment with 2% Topical Ganciclovir Solution in Cytomegalovirus Anterior Uveitis and Corneal Endotheliitis.

Purpose: This study aimed to evaluate the therapeutic efficacy and long-term outcomes of treatment with topical 2% ganciclovir solution in immunocompetent patients with aqueous humor polymerase chain reaction (PCR)-proven cytomegalovirus (CMV) anterior uveitis and corneal endotheliitis. Methods: We retrospectively reviewed the findings for immunocompetent patients diagnosed with CMV uveitis or endotheliitis based on clinical manifestations and polymerase chain reaction (PCR) examination results and treated with topical 2% ganciclovir solution at National Cheng Kung University Hospital. Clinical outcome measurements included evaluations of the response rate, relapses, resolution of anterior chamber inflammation, visual acuity, and intraocular pressure. Results: The study included 38 eyes of 32 patients. Long-term administration of topical 2% ganciclovir significantly decreased keratic precipitates (p = 0.001), anterior chamber cells (p = 0.001), and reduced intraocular pressure (p < 0.001). Only one eye was unresponsive to topical ganciclovir treatment, and the recurrence decreased to 0.13 relapses per year. The presence of keratic precipitates and higher intraocular pressure at the initial presentation were significantly associated with recurrence (p = 0.036 and p = 0.001, respectively). Conclusions: Long-term use of topical 2% ganciclovir solution is effective, safe, and applicable when commercialized ganciclovir gel is not available.

Proton Beam Therapy in Managing Unresectable Hepatocellular Carcinoma with Bile Duct Invasion.

Hepatocellular carcinoma (HCC) with bile duct invasion is a rare and notorious subtype of HCC. This study included patients that had unresectable HCC with bile duct invasion and proton beam therapy between November 2015 and February 2021. Twenty patients fit the inclusion criteria. The median tumor size was 6.3 cm. Nine patients (45.0%) had major vascular invasions. All included patients received the radiation dose of 72.6 gray relative biological effectiveness due to the proximity of porta hepatis and tumor. The median follow-up time was 19.9 months. The median overall survival was 19.9 months among deceased patients. The 1-year cumulative local recurrence rates were 5.3%, with only two patients developing in-field failure. The 1-year and 2-year overall survival rates were 79.4% and 53.3%. The 1-year progression-free survival was 58.9%. Four patients developed radiation-induced liver disease. The 1-year cholangitis-free survival was 55.0%. Skin toxicity was the most common acute toxicity and rarely severe. Eight patients developed ≤ grade 3 gastrointestinal ulcers. Proton beam therapy offers desirable survival outcomes for unresectable HCC patients with bile duct invasion. Optimal local tumor control could also be obtained within acceptable toxicities.

Susac Syndrome Following COVID-19 Vaccination: A Case Report.

Due to the COVID-19 pandemic, numerous vaccines have been developed for the disease. However, with large-scale vaccination has come the gradual emergence of immunological phenomena caused by these new vaccines. Herein, we report a 48-year-old female with a sudden onset of inferior visual field defects in the left eye following her first dose of the ChAdOx1 vaccine. Dilated fundus examination combined with optical coherence tomography and fluorescein angiography confirmed the diagnosis of branch retinal artery occlusion. Within 4 weeks following vaccination, symptoms associated with hearing impairment developed, and magnetic resonance imaging revealed leptomeningeal enhancement. The diagnosis of Susac syndrome (SS) was confirmed. The development of SS may be caused by endotheliopathy resulting from the molecular mimicry of the ChAdOx1 vaccine. Clinicians should be aware of the symptoms of SS, which may develop after COVID-19 vaccination. Further experimental surveillance and case-control studies are required to confirm this relationship.

THαß Immunological Pathway as Protective Immune Response against Prion Diseases: An Insight for Prion Infection Therapy.

Prion diseases, including Creutzfeldt-Jakob disease, are mediated by transmissible proteinaceous pathogens. Pathological changes indicative of neuro-degeneration have been observed in the brains of affected patients. Simultaneously, microglial activation, along with the upregulation of pro-inflammatory cytokines, including IL-1 or TNF-α, have also been observed in brain tissue of these patients. Consequently, pro-inflammatory cytokines are thought to be involved in the pathogenesis of these diseases. Accelerated prion infections have been seen in interleukin-10 knockout mice, and type 1 interferons have been found to be protective against these diseases. Since interleukin-10 and type 1 interferons are key mediators of the antiviral THαß immunological pathway, protective host immunity against prion diseases may be regulated via THαß immunity. Currently no effective treatment strategies exist for prion disease; however, drugs that target the regulation of IL-10, IFN-alpha, or IFN-ß, and consequently modulate the THαß immunological pathway, may prove to be effective therapeutic options.

Disruption of the Francisella noatunensis subsp. orientalis pdpA Gene Results in Virulence Attenuation and Protection in Zebrafish.

Several Francisella spp., including Francisella noatunensis, are regarded as important emerging pathogens of wild and farmed fish. However, very few studies have investigated the virulence factors that allow these bacterial species to be pathogenic in fish. The Francisella pathogenicity island (FPI) is a well-described, gene-dense region encoding major virulence factors for the genus Francisella. pdpA is a member of the pathogenicity-determining protein genes carried by the FPI that are implicated in the ability of the mammalian pathogen Francisella tularensis to escape and replicate in infected host cells. Using a sacB suicide approach, we generated pdpA knockouts to address the role of PdpA as a virulence factor for F. noatunensis. Because polarity can be an issue in gene-dense regions, we generated two different marker-based mutants in opposing polarity (the F. noatunensis subsp. orientalis ΔpdpA1 and ΔpdpA2 strains). Both mutants were attenuated (P < 0.0001) in zebrafish challenges and displayed impaired intracellular replication (P < 0.05) and cytotoxicity (P < 0.05), all of which could be restored to wild-type (WT) levels by complementation for the ΔpdpA1 mutant. Importantly, differences were found for bacterial burden and induction of acute-phase and proinflammatory genes for the F. noatunensis subsp. orientalis ΔpdpA1 and ΔpdpA2 mutants compared to the WT during acute infection. In addition, neither mutant resulted in significant histopathological changes. Finally, immunization with the F. noatunensis subsp. orientalis ΔpdpA1 mutant led to protection (P < 0.012) against an acute 40% lethal dose (LD40) challenge with WT F. noatunensis in the zebrafish model of infection. Taken together, the results from this study further demonstrate physiological similarities within the genus Francisella relative to their phylogenetic relationships and the utility of zebrafish for addressing virulence factors for the genus.

Prognostic significance of dynamic changes in lymphocyte-to-monocyte ratio in patients with head and neck cancer treated with radiotherapy: results from a large cohort study.

BACKGROUND AND PURPOSE: We sought to investigate whether dynamic changes in lymphocyte-to-monocyte ratio (LMR) occurring during the course of radiotherapy (RT) may have prognostic value in patients with head and neck cancer (HNC). MATERIALS AND METHODS: We retrospectively reviewed the clinical records of patients with HNC who underwent RT at our center between 2005 and 2013. Generalized estimating equations were used to longitudinally assess changes in LMR through the course of RT. Delta-LMR was calculated as the difference between LMR measured during treatment and baseline LMR values. Freedom from metastasis (FFM) and overall survival (OS) served as the main outcome measures. RESULTS: A total of 1431 patients with HNC were enrolled. After a median follow-up of 9 years, 636 (44.4%) patients died and 240 (16.8%) had distant metastases. Compared with patients with low delta-LMR at two weeks, those with high delta-LMR experienced less favorable outcomes (five-year OS: 73% versus 59%, respectively, p < 0.001; five-year FFM: 87% versus 80%, respectively, p = 0.015). Similar findings were observed for delta-LMR measured at four weeks (five-year OS: 72% versus 60%, p < 0.001; five-year FFM: 86% versus 79%, respectively, p = 0.002) and six weeks (five-year OS: 72% versus 57%, p < 0.001; five-year FFM: 87% versus 79%, respectively, p = 0.002). Multivariate analysis identified delta-LMR as an independent prognostic factor for both FFM and OS. CONCLUSION: Delta-LMR is a simple and inexpensive biomarker that may be clinically useful for predicting FFM and OS in patients with HNC treated with RT.

Prognostic significance of the preoperative systemic immune-inflammation index in patients with oral cavity squamous cell carcinoma treated with curative surgery and adjuvant therapy.

OBJECTIVES: To investigate the prognostic value of the preoperative systemic immune-inflammation index (SII) in patients with oral cavity squamous cell carcinoma (OC-SCC) treated with curative surgery followed by adjuvant radiotherapy (RT) or chemoradiotherapy (CCRT). MATERIALS AND METHODS: We retrospectively reviewed the clinical records of patients with OC-SCC who received surgery and postoperative adjuvant RT/CCRT between January 2005 and December 2012. Blood samples were drawn in the 2 weeks preceding surgery. SII was calculated by multiplying the absolute neutrophil and platelet counts, and then, divided by the absolute lymphocyte count, and its optimal cutoff value was identified using the Youden's index. The study endpoints included overall survival (OS), local control (LC), regional control (RC), and distant control (DC). RESULTS: The study sample consisted of 993 patients (58.8% of them treated with CCRT). The optimal cutoff value for SII was 810.6. A total of 347 (34.9%) study participants had high preoperative SII values. After allowance for potential confounders in multivariable analysis, high SII values were independently associated with less favorable DC (adjusted hazard ratio [HR] = 1.683, p = 0.001) and OS (adjusted HR = 1.466, p < 0.001). No independent association between SII and LC/RC was observed. CONCLUSION: Increased SII values predict poor DC and OS in patients with OC-SCC treated with curative resection and adjuvant RT/CCRT. Owing to the higher risk of systemic failure in this patient group, a thorough follow-up surveillance schedule may be advisable pending independent confirmation of our data.

Influence of Resveratrol on the Cardiovascular Health Effects of Chronic Kidney Disease.

Cardiovascular disease (CVD) is closely related to chronic kidney disease (CKD), and patients with CKD have a high risk of CVD-related mortality. Traditional CVD risk factors cannot account for the higher cardiovascular risk of patients with CKD, and standard CVD interventions cannot reduce the mortality rates among patients with CKD. Nontraditional factors related to mineral and vitamin-D metabolic disorders provide some explanation for the increased CVD risk. Non-dialyzable toxins, indoxyl sulfate (IS) and p-cresol sulfate (PCS)-produced in the liver by colonic microorganisms-cause kidney and vascular dysfunction. Plasma trimethylamine-N-oxide (TMAO)-a gut microbe-dependent metabolite of dietary L-carnitine and choline-is elevated in CKD and related to vascular disease, resulting in poorer long-term survival. Therefore, the modulation of colonic flora can improve prospects for patients with CKD. Managing metabolic syndrome, anemia, and abnormal mineral metabolism is recommended for the prevention of CVD in patients with CKD. Considering nontraditional risk factors, the use of resveratrol (RSV), a nutraceutical, can be helpful for patients with CVD and CKD. This paper discusses the beneficial effects of RSV on biologic, pathophysiological and clinical responses, including improvements in intestinal epithelial integrity, modulation of the intestinal microbiota and reduction in hepatic synthesis of IS, PCS and TMAO in patients with CVD and CKD.

Prognostic value of lymph node to primary tumor standardized uptake value ratio in unresectable esophageal cancer.

BACKGROUND: Unresectable esophageal cancer harbors high mortality despite chemoradiotherapy. Better patient selection for more personalized management may result in better treatment outcomes. We presume the ratio of maximum standardized uptake value (SUV) of metastatic lymph nodes to primary tumor (NTR) in 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) may provide prognostic information and further stratification of these patients. METHODS: The patients with non-metastatic and unresectable esophageal squamous cell carcinoma (SCC) receiving FDG PET/CT staging and treated by chemoradiotherapy were retrospectively reviewed. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cut-off value for NTR. Kaplan-Meier method and Cox regression model were used for survival analyses and multivariable analyses, respectively. RESULTS: From 2010 to 2016, 96 eligible patients were analyzed. The median follow-up time was 10.2 months (range 1.6 to 83.6 months). Using ROC analysis, the best NTR cut-off value was 0.46 for prediction of distant metastasis. The median distant metastasis-free survival (DMFS) was significantly lower in the high-NTR group (9.5 vs. 22.2 months, p = 0.002) and median overall survival (OS) (9.5 vs. 11.6 months, p = 0.013) was also significantly worse. Multivariable analysis revealed that NTR was an independent prognostic factor for DMFS (hazard ratio [HR] 1.81, p = 0.023) and OS (HR 1.77, p = 0.014). CONCLUSIONS: High pretreatment NTR predicts worse treatment outcomes and could be an easy-to-use and helpful prognostic factor to provide more personalized treatment for patients with non-metastatic and unresectable esophageal SCC.

A scoping review of medical education research for residents in radiation oncology.

BACKGROUND: Both medical education and radiation oncology have progressed significantly in the past decade, but a generalized overview of educational research for radiation oncology residents has not been produced. This study examines recent research trends in medical education for residents in radiation oncology through a scoping review. METHODS: We conducted a scoping review of medical education research for residents in radiation oncology to survey the research trends. We used publications available on MEDLINE, PubMed, and Scopus to conduct this scoping review. RESULTS: We screened 221 full-text articles, 146 of which met our inclusion criteria. These publications showed increased activity in medical education research for residents, most involving affiliations in the United States. We identified persistent interest in training-, contouring-, and technology-related issues. An increase in research related to career, treatment quality, and multidisciplinary training was also observed. However, no research about teacher training was identified. CONCLUSIONS: This scoping review presents the trends in study interests among stakeholders of medical education research in radiation oncology. With an investigation of existing studies, this research identifies areas of high priority and a lack of studies about teacher training. This study provides potential future directions for medical education research for residents in radiation oncology.

MEH-PPV photophysics: insights from the influence of a nearby 2D quencher.

The effect of 2D quenching on single chain photophysics was investigated by spin coating 13 nm thick films of polystyrene lightly doped with MEH-PPV onto CVD grown graphene and observing the changes in several photoluminescent (PL) observables. With 99% of the PL quenched, we found a 60% drop in the PL lifetime, along with a significant blue-shift of the PL emission due to the preferential quenching of emission at longer wavelengths. During photo-bleaching, the blue spectral shift observed for isolated polymers was eliminated in the presence of the quencher up until 70% of the polymer was photo-bleached. Results were interpreted using a static disorder induced conjugation length distribution model. The quencher, by opening up a new non-radiative decay channel, ensures that excitons do not have sufficient time to migrate to nearby lower energy chromophores. The reduction of energy transfer into the lowest-energy chromophores thus reduces their rate of photo-bleaching. Finally, the difference between the quenched and non-quenched spectra allows the rate of energy transfer along the polymer backbone to be estimated at ∼2 ns-1.

How small is TOO small? New liver constraint is needed- Proton therapy of hepatocellular carcinoma patients with small normal liver.

PURPOSE: This study evaluated the outcomes of hepatocellular carcinoma (HCC) patients with small normal liver volume (NLV) treated with proton beam therapy (PBT) and introduced estimated standard liver volume (eSLV) as a new constraint. MATERIALS AND METHODS: HCC patients with NLV < 800 cm3 and no distant metastasis who received treatment in our proton center were included. The doses of PBT were mainly 72.6 Gray equivalents (GyE) in 22 fractions and 66 GyE in 10 fractions according to tumor locations. The Urata equation was used to calculate eSLV. RESULTS: Twenty-two patients were treated between November 2015 and December 2016. The 1-year progression-free and overall survival rates were 40.4% and 81.8%, respectively. The 1-year in-field failure-free rate was 95.5%. NLV ranged from 483.9 to 795.8 cm3 (median = 673.8 cm3), eSLV ranged from 889.3 to 1290.0 cm3 (median = 1104.5 cm3), and the resulting NLV/eSLV ratio ranged from 44.3 to 81.2% (median = 57.7%). Non-irradiated liver volume (NILV) ranged from 232.9 to 531.6 cm3 (median = 391.2 cm3). The NILV/eSLV ratio ranged from 21.2 to 48.0% (median = 33.3%). NLV in the patients who received <30 GyE (rV30) ranged from 319.1 to 633.3 cm3 (median = 488.2 cm3), and their rV30/eSLV ratio ranged from 30.7 to 58.0%. None of our patients developed liver failure. One patient with initial abnormal liver enzyme levels developed non-classic radiation-induced liver disease (RILD). CONCLUSION: From the viewpoint of minimal liver toxicity occurring in our patients with NLV < 800 cm3, conventional liver constraints involving the use of absolute volume could not accurately predict the risk of RILD. It is reasonable to start using individualized constraints with eSLV for HCC patients undergoing PBT. According to the study results, an NILV/eSLV ratio of >20% and an rV30/eSLV ratio of >30% are acceptable.

Impact of a narrative medicine programme on healthcare providers' empathy scores over time.

BACKGROUND: The cultivation of empathy for healthcare providers is an important issue in medical education. Narrative medicine (NM) has been shown to foster empathy. To our knowledge, there has been no research that examines whether a NM programme affects multi-professional healthcare providers' empathy. Our study aims to fill this gap by investigating whether a NM programme effects multi-professional healthcare providers' empathy. METHODS: A pre-post questionnaire method was used.142 participants (n = 122 females) who attended the NM programme were divided into single (n = 58) and team groups (n = 84) on the basis of inter-professional education during a period of 2 months. Perceptions of the NM programme were collected using our developed questionnaire. Empathy levels were measured using the Chinese version of Jefferson Scale of Empathy - Healthcare Providers Version (JSE-HP) - at three time points: prior to (Time 1), immediately after (T2), and 1.5 years (T3) after the programme. RESULTS: Participants' perceptions about the NM programme (n = 116; n = 96 females) suggested an in enhancement of empathy (90.5%). Empathy scores via the JSE-HP increased after the NM programme (T1 mean 111.05, T2 mean 116.19) and were sustainable for 1.5 years (T3 mean 116.04) for all participants (F(2297) = 3.74, p < .025). A main effect of gender on empathy scores was found (F(1298) = 5.33, p < .022). No significant effect of gender over time was found but there was a trend that showed females increasing empathy scores at T2, sustaining at T3, but males demonstrating a slow rise in empathy scores over time. CONCLUSIONS: NM programme as an educational tool for empathy is feasible. However, further research is needed to examine gender difference as it might be that males and females respond differently to a NM programme intervention.

Controlling photoluminescent emission from polymer membranes through the creation of local deformation zones.

Understanding and optimizing light propagation and extraction in light-emitting systems, such as fluorescent chemical sensors, is important for the production of more efficient sensors. We apply Monte Carlo ray tracing to model the effects of one-dimensional perturbations of film thickness on the luminescent emission (spatial, directional, spectral) of a freestanding transparent polymer film embedded with luminescent chromophores. Such modification not only enhances light extraction but also allows its location and direction to be controlled. Optimization of the deformation geometry allows for a 3.6-fold increase in intensity for a far-field detector.

Bioassisted synthesis of catalytic gold/silica nanotubes using layer-by-layer assembled polypeptide templates.

We report the bioassisted synthesis of gold nanoparticle/silica (Au NP/silica) tubes using layer-by-layer (LBL) assembled poly(L-lysine)/poly(L-tyrosine) (PLL/PLT) multilayer films deposited on the polycarbonate (PC) membrane pores as both mediating agents and templates. The novelty of this approach is the in situ synthesis of Au NP/silica tubes using PLL/PLT multilayer films for sequential growth of Au NPs and silicas. The experimental data revealed that the buildup of the LBL multilayer films was mainly driven by the formation of hydrogen bond and the polypeptide macromolecular assemblies adopted mainly ß-sheet conformation. The as-prepared Au NP/silica tubes possessed promising catalytic activity toward the reduction of p-nitrophenol. The synthesis conditions such as the concentration of gold precursor and polypeptide molecular weight were found to influence the gold weight ratio and particle size in the tubes and the catalytic properties of the Au NP/silica tubes. This approach provides a facile, robust, and green method to obtain nonaggregated metal nanoparticles immobilized in porous oxide network at ambient conditions. Using the synergy between biomimetic or bioassisted synthesis of nanostructured materials and LbL assembly technique, a variety of structures such as films, tubes, and capsules comprising of multiple compositions can be obtained.

Layer-by-layer polypeptide macromolecular assemblies-mediated synthesis of mesoporous silica and gold nanoparticle/mesoporous silica tubular nanostructures.

A simple and versatile approach is proposed to use the LbL-assembled polypeptide macromolecular assemblies as mediating agents and templates for directed growth of gold nanoparticles and biomimetic silica mineralization, allowing the synthesis of polypeptide/silica and polypeptide/gold nanoparticle/silica composite materials, as well as mesoporous silica (meso-SiO2) and gold nanoparticle/mesoporous silica (Au NP/meso-SiO2). The formation of tubular nanostructures was demonstrated by silicification and growth of gold nanoparticles within macromolecular assemblies formed by poly(L-lysine) (PLL) and poly(L-glutamic acid) (PLGA) using polycarbonate membranes as templates. The experimental data revealed that the silicified macromolecular assemblies adopted mainly sheet/turn conformation. The as-prepared mesoporous silica materials possessed well-defined tubular structures with pore size and porosity depending on the size of sheet/turn aggregates, which is a function of the molecular weight of polypeptides. The directed growth of Au NP and subsequent silica mineralization in the macromolecular assembly resulted in Au NP/meso-SiO2 tubes with uniform nanoparticle size and the as-prepared materials exhibited promising catalytic activity toward the reduction of p-nitrophenol. This approach provides a facile and general method to synthesize organic-inorganic composite materials, oxide and metal-oxide nanomaterials with different compositions and structures.