Association between phosphodiesterase type 5 inhibitors use and risk of melanoma: a meta-analysis

This meta-analysis aimed to clarify the actual association between the phosphodiesterase type 5 inhibitors (PDE5-Is) use and the risk of melanoma in erectile dysfunction (ED) patients. A systematic literature search was conducted in online databases in October, 2016 to identify studies focusing on the association between PDE5-Is use and the risk of melanoma. Summarized multivariate adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to assess the strength of associations. A total of six clinical trials containing more than one million participants were included. ED patients  using PDE5-Is shared a significant high risk of melanoma (RR=1.12, 95% CI=1.03-1.21, p=0.006). Positive associations were observed in all kinds of prescriptions: single prescription (RR=1.20, 95% CI=1.06-1.35, p=0.003), medium number of prescription (RR=1.15, 95% CI=1.01-1.30, p=0.03), and high number of prescription (RR=1.18, 95% CI=1.05-1.34, P=0.006). Additionally, PDE5-Is were also found to be significantly associated with increased risk of basal cell carcinoma (RR=1.14, 95% CI=1.09-1.19, p<0.00001). Our study indicates that PDE5-Is use could significantly increase the risk of melanoma and basal cell carcinoma. However, the risk of melanoma did not rise significantly with the increased number of prescriptions. Consequently, owing to the lack of information about other potential synergistic factors, it is difficult for us to make a solid conclusion that application of PDE5-Is is the direct cause of increased risk of melanoma. Their relationship needs to be validated by further evidences.

Biochar-Mediated Anaerobic Oxidation of Methane

Biochar was recently identified as an effective soil amendment for CH₄ capture. Corresponding mechanisms are currently recognized to be from physical properties of biochar, providing a favorable growth environment for aerobic methanotrophs which perform aerobic methane (CH₄) oxidation. However, our study shows that the chemical reactivity of biochar can also stimulate anaerobic oxidation of CH₄ (AOM) by anaerobic methanotrophic archaea (ANME) of ANME-2d, which proposes another plausible mechanism for CH₄ mitigation by biochar amendment in anaerobic environments. It was found that, by adding biochar as the sole electron acceptor in an anaerobic environment, CH₄ was biologically oxidized, with CO₂ production of 106.3 ± 5.1 μmol g^-1 biochar. In contrast, limited CO₂ production was observed with chemically reduced biochar amendment. This biological nature of the process was confirmed by mcr gene transcript abundance as well as sustained dominance of ANME-2d in the microbial community during microbial incubations with active biochar amendment. Combined FTIR and XPS analyses demonstrated that the redox activity of biochar is related to its oxygen-based functional groups. On the basis of microbial community evolution as well as intermediate production during incubation, different pathways in terms of direct or indirect interactions between ANME-2d and biochar were proposed for biochar-mediated AOM.

Prevalence, distribution and risk factors of farmer reported swine influenza infection in Guangdong Province, China

A cross-sectional study was undertaken to better understand the husbandry, management and biosecurity practices of pig farms in Guangdong Province (GD), China to identify risk factors for farmer reported swine influenza (SI) on their farms. Questionnaires were administered to 153 owners/managers of piggeries (average of 7 from each of the 21 prefectures in GD). Univariable and multivariable logistic regression analyses were used to identify risk factors for farmer reported SI in piggeries during the six months preceding the questionnaire administration. The ability of wild birds to enter piggeries (OR 2.50, 95% CI: 1.01-6.16), the presence of poultry on a pig-farm (OR 3.24, 95% CI: 1.52-6.94) and no biosecurity measures applied to workers before entry to the piggery (OR 2.65, 95% CI: 1.04-6.78) were found to increase the likelihood of SI being reported by farmers in a multivariable logistic regression model. The findings of this study highlight the importance of understanding the local pig industry and the practices adopted when developing control measures to reduce the risk of SI to pig farms.

Downregulation of SPARC Is Associated with Epithelial-Mesenchymal Transition and Low Differentiation State of Biliary Tract Cancer Cells

BACKGROUND

Biliary tract cancers (BTCs) have a poor prognosis. BTCs are characterized by a prominent desmoplastic reaction which possibly contributes to the aggressive phenotype of this tumor. The desmoplastic reaction includes excessive production and deposition of extracellular matrix proteins such as periostin, secreted protein acidic and rich in cysteine (SPARC), thrombospondin-1, as well as accumulation of α-smooth muscle actin-positive cancer-associated fibroblasts and immune cells, secreting growth factors and cytokines including transforming growth factor (TGF)-β. In the present study, we investigated the expression of SPARC in BTC as well as its possible regulation by TGF-β.

METHODS

Expression levels of Sparc, TGF-β1 and its receptor ALK5 were evaluated by quantitative real-time PCR in 6 biliary tract cell lines as well as 1 immortalized cholangiocyte cell line (MMNK-1). RNAs from tumor samples of 7 biliary tract cancer patients were analyzed for expression of Sparc, TGF-β type II receptor (TbRII) as well as Twist and ZO-1. MMNK-1 cells were stimulated with TGF-β for 24 h, and Sparc, ZO-1 and E-Cadherin expressions were determined. The presence of SPARC protein was analyzed by immunohistochemistry in tumor specimens from 10 patients.

RESULTS

When comparing basal Sparc transcript levels in diverse BTC cell lines to MMNK-1 cells, we found that it was strongly downregulated in all cancer cell lines. The remaining expression levels were higher in highly differentiated cell lines (CCSW1, MZChA1, MZChA2 and TFK-1) than in less differentiated and undifferentiated ones (BDC, SKChA1). Expression of Sparc in BTC patient samples showed a significant positive correlation with expression of the epithelial marker ZO-1. In contrast, the mesenchymal marker Twist and the TbRII showed a trend of negative correlation with expression of Sparc in these samples. TGF-β exposure significantly downregulated Sparc expression in MMNK-1 cholangiocytes in vitro in parallel to downregulation of epithelial markers (E-Cadherin and ZO-1). Finally, SPARC immunostaining was performed in 10 patient samples, and the correlation between absence of SPARC and survival times was analyzed.

CONCLUSIONS

These data imply that a decrease in SPARC expression is correlated with dedifferentiation of BTC cells resulting in enhanced EMT being possibly mediated by TGF-β. Thereby SPARC levels might be a marker for individual prognosis of a patient, and strategies aiming at inhibition of SPARC downregulation might have potential for new future therapies.

Hydrothermal treatment of lincomycin mycelial residues: Antibiotic resistance genes reduction and heavy metals immobilization

In this study, fate of antibiotic resistance genes (ARGs - lmrA, lmrB, ermB, lnuA, lnuB and vgaC) and species distribution of heavy metals during lincomycin mycelial residues hydrothermal treatment (HT) process were investigated. The results showed that HT could reduce both ARGs and mobile genetic elements effectively by 1.02 to 4.14 logs. Total bacterial biomass reflecting by 16S rRNA decreased from 1.27 × 10⁹ to 4.47 × 10⁵ copies g^-1 dry weight. Moreover, half-lives of these targets varied from 2.4 min (ermB) to 8.9 min (lmrB) in the first 30 min of treatment based on a biphasic first-order kinetic model. After the first 30 min, however, half-lives ranged between 15.4 min (lmrA) and 247.6 min (ISCR1). Complexation and precipitation resulted in the transformation of heavy metals from weakly bounded to relatively stable fraction in HT process. Simultaneously, their environmental risk level decreased by at least one grade.

Narrowband Ultraviolet Photodetectors Based on Nanocomposite Thin Films with High Gain and Low Driving Voltage

Narrowband ultraviolet (UV) photodetectors are highly desired in multiple areas. Photodetectors based on organic-inorganic nanocomposites offer high sensitivity, widely adjustable response range, light weight, and low-temperature solution processibility. However, the broad absorption range of organic and inorganic semiconductor materials makes it difficult to achieve a narrowband detection feature for nanocomposite photodetectors. In this work, nanocomposite thin films containing the wide band gap conjugated polymer poly[(9,9-dioctylfluorenyl-2,7-diyl)- alt- co-(bithiophene)] (F8T2) blended with wide band gap ZnO nanoparticles (NPs) serve as the active layers of the photodetectors. Narrowband UV photodetectors with high gain and low driving voltage are demonstrated by adopting a symmetric device structure, controlling the active layer composition and microstructure, and manipulating the light penetration depth in the active layer. The fabricated photodetector exhibits a high external quantum efficiency of 782% at 358 nm under a low forward bias of 3 V with the full-width at half-maximum of 16 nm. Combined with a low dark current, a high specific detectivity of 8.45 × 10¹² Jones is achieved. The impacts of the F8T2:ZnO NPs weight ratio and the device structure on the UV-selectivity and the device performance are investigated and discussed. Our method offers a pathway to design and fabricate narrowband UV photodetectors.

Effect of methane partial pressure on the performance of a membrane biofilm reactor coupling methane-dependent denitrification and anammox

Complete nitrogen removal has recently been demonstrated by integrating anaerobic ammonium oxidation (anammox) and denitrifying anaerobic methane oxidation (DAMO) processes. In this work, the effect of methane partial pressure on the performance of a membrane biofilm reactor (MBfR) consisting of DAMO and anammox microorganisms was evaluated. The activities of DAMO archaea and DAMO bacteria in the biofilm increased significantly with increased methane partial pressure, from 367 ± 9 and 58 ± 22 mg-N L^-1d^-1 to 580 ± 12 and 222 ± 22 mg-N L^-1d^-1, respectively, while the activity of anammox bacteria only increased slightly, when the methane partial pressure was elevated from 0.24 to 1.39 atm in the short-term batch tests. The results were supported by a long-term (seven weeks) continuous test, when the methane partial pressure was dropped from 1.39 to 0.78 atm. The methane utilization efficiency was always above 96% during both short-term and long-term tests. Taken together, nitrogen removal rate (especially the nitrate reduction rate by DAMO archaea) and methane utilization efficiency could be maintained at high levels in a broad range of methane partial pressure (0.24-1.39 atm in this study). In addition, a previously established DAMO/anammox biofilm model was used to analyze the experimental data. The observed impacts of methane partial pressure on biofilm activity were well explained by the modeling results. These results suggest that methane partial pressure can potentially be used as a manipulated variable to control reaction rates, ultimately to maintain high nitrogen removal efficiency, according to nitrogen loading rate.

Investigating the environmental risks from the use of spray-dried cephalosporin mycelial dreg (CMD) as a soil amendment

Cephalosporin mycelial dreg (CMD) is a by-product of the pharmaceutical industry. Spray-drying is widely used for the dewatering process prior to the application of CMD as a soil amendment. However, the potential environmental behaviors and risks of spray-dried CMD amendment remain unclear. Here, a lab-scale incubation experiment was conducted to investigate the salinity, phytotoxicity, introduced antibiotics, heavy metals and the potential impacts of resistance genes in CMD-amended soil. Spray-dried CMD amendment generally increased soil salinity and only high dosed soils showed phytotoxic effects at the end of the incubation period, implying the physiological damage to plant growth. The introduced antibiotics quickly degraded over time, indicating a relatively low environmental persistence. Heavy metal slightly increased in soil receiving spray-dried CMD, and regulations should be developed to avoid metal accumulation. A decreased diversity and distinct patterns of β-lactam resistance genes as well as a dose-effect of their enrichment were observed in CMD-amended soil, which might be partially explained by the specific metals and introduced antibiotics. Antibiotic resistance genes in soil may be a valuable tool for evaluating the environmental risk associated with use of CMD as a soil amendment.

Assessing the safety of thermally processed penicillin mycelial dreg following the soil application: Organic matter's maturation and antibiotic resistance genes

To degrade the residual penicillin G in penicillin mycelial dreg (PMD), thermal treatment was used as a pretreatment for practical disposal. Given that the characteristics of treated-PMD aren't adequately clear, a lab-scale experiment was conducted to verify its safety assessment for land application under the following points: (i) variation of penicillin G residue (ii) maturity of organic matter (OM) (iii) phytotoxicity (iv) abundance of antibiotic resistance genes (ARGs). A high-throughput quantitative polymerase chain reaction (HT-qPCR) method was used to perform an overall investigation of soil ARGs. The results show that heat treatment effectively degrades 98% of penicillin in PMD within 120 min. After thermal treatment, the treated-PMD was applied to soil. The original penicillin level was considerably lower and completely degraded within 4 days. Variation of germination index (GI) implied that the created phytotoxicity was significantly reduced. Furthermore, compared with PMD, the addition of treated-PMD didn't cause enrichment of soil ARGs in diversity and abundance. Therefore, heat treatment can be considered as an effective pretreatment for PMD practical application.

Creating a functional single-chromosome yeast

Eukaryotic genomes are generally organized in multiple chromosomes. Here we have created a functional single-chromosome yeast from a Saccharomyces cerevisiae haploid cell containing sixteen linear chromosomes, by successive end-to-end chromosome fusions and centromere deletions. The fusion of sixteen native linear chromosomes into a single chromosome results in marked changes to the global three-dimensional structure of the chromosome due to the loss of all centromere-associated inter-chromosomal interactions, most telomere-associated inter-chromosomal interactions and 67.4% of intra-chromosomal interactions. However, the single-chromosome and wild-type yeast cells have nearly identical transcriptome and similar phenome profiles. The giant single chromosome can support cell life, although this strain shows reduced growth across environments, competitiveness, gamete production and viability. This synthetic biology study demonstrates an approach to exploration of eukaryote evolution with respect to chromosome structure and function.

Knockout of tnni1b in zebrafish causes defects in atrioventricular valve development via the inhibition of the myocardial wnt signaling pathway

The proper development of atrioventricular (AV) valves is critical for heart morphogenesis and for the formation of the cardiac conduction system. Defects in AV valve development are the most common type of congenital heart defect. Cardiac troponin I ( ctnni), a structural and regulatory protein involved in cardiac muscle contraction, is a subunit of the troponin complex, but the functions and molecular mechanisms of ctnni during early heart development remain unclear. We created a knockout zebrafish model in which troponin I type 1b ( tnni1b) ( Tnni-HC, heart and craniofacial) was deleted using the clustered regularly interspaced short palindromic repeat/clustered regularly interspaced short palindromic repeat-associated protein system. In the homozygous mutant, the embryos showed severe pericardial edema, malformation of the heart tube, reduction of heart rate without contraction and with almost no blood flow, heart cavity congestion, and lack of an endocardial ring or valve leaflet, resulting in 88.8 ± 6.0% lethality at 7 d postfertilization. Deletion of tnni1b caused the abnormal expression of several markers involved in AV valve development, including bmp4, cspg2, has2, notch1b, spp1, and Alcam. Myocardial re-expression of tnni1b in mutants partially rescued the pericardial edema phenotype and AV canal (AVC) developmental defects. We further showed that tnni1b knockout in zebrafish and ctnni knockdown in rat h9c2 myocardial cells inhibited cardiac wnt signaling and that myocardial reactivation of wnt signaling partially rescued the abnormal expression of AVC markers caused by the tnni1b deletion. Taken together, our data suggest that tnni1b plays a vital role in zebrafish AV valve development by regulating the myocardial wnt signaling pathway.-Cai, C., Sang, C., Du, J., Jia, H., Tu, J., Wan, Q., Bao, B., Xie, S., Huang, Y., Li, A., Li, J., Yang, K., Wang, S., Lu, Q. Knockout of tnni1b in zebrafish causes defects in atrioventricular valve development via the inhibition of myocardial wnt signaling pathway.

Clofazimine improves clinical outcomes in multidrug-resistant tuberculosis: a randomized controlled trial

OBJECTIVES

We carried out a randomized multicentre study in China to investigate whether the clofazimine would improve the efficacy of the standardized regimen in patients with multidrug-resistant tuberculosis (MDR-TB).

METHODS

Patients with MDR-TB managed in 17 TB specialist hospitals in China between September 2009 and September 2011 were randomly assigned to the treatment groups at enrolment. In the intervention group, 100 mg clofazimine per day was added to the standardized regimen. The primary outcome was the proportion of patients with successful outcomes.

RESULTS

From the 156 patients that were screened, 74 were assigned to the control group and 66 to the clofazimine group. Of the 66 cases analysed for clinical outcome in the clofazimine group, 36 patients were cured, and seven completed treatment, yielding a favourable outcome rate of 65.1%. The proportion of patients with favourable outcomes receiving the control regimen was 47.3% (35/74), which was significantly lower than that in the clofazimine group (p 0.034, relative risk 0.661, 95% CI 0.243-0.949).

CONCLUSIONS

The addition of clofazimine to the standard regimen improved the treatment of MDR-TB.

Flexible Narrowband Ultraviolet Photodetectors with Photomultiplication Based on Wide Band Gap Conjugated Polymer and Inorganic Nanoparticles

Lightweight and flexible ultraviolet (UV) photodetectors (PDs) have wide applications and have attracted more attention. PDs using organic and inorganic nanocomposites as active layers with a photodiode configuration could achieve photomultiplication and narrowband photoresponse via the control of microstructure and thickness of active layers. Here, we fabricated flexible UV PDs on indium tin oxide-coated poly(ethylene terephthalate) substrates with a nanocomposite active layer composed of ZnO nanoparticles blended with a wide band gap conjugated polymer, poly[(9,9-dioctylfluorenyl-2,7-diyl)- alt- co-(bithiophene)] (F8T2). As a result of the wavelength-dependent penetration depth of light in the active layer, the fabricated flexible UV PDs showed two narrow response peaks at 360 and 510 nm under reverse biases in the external quantum efficiency (EQE) spectra with full width at half maximum (FWHM) less than 20 nm. Both responses exhibited greater than 100% EQE, indicating a photomultiplication effect, whereas the UV response at 360 nm was 10 times stronger under -15 V bias. The fabricated flexible UV PDs were bent under both tensile and compressive stress to a curvature of 2.1 cm^-1, each with 50 repetitions. The peak specific detectivity ( D*) only decreased by about 5% in total, the FWHM was well retained below 20 nm and the response speed remained almost constant after two types of bending, demonstrating mechanical flexibility and photoresponse stability of the fabricated flexible UV PDs. The photodiode configuration with nanocomposite active layers offers a promising route to make flexible and conformable narrowband, photomultiplication-type photodetectors for modern applications.

Defective Treg response in acute kidney injury was caused by a reduction in TIM-3+ Treg cells

BACKGROUND

Despite years of research, the treatment of acute kidney injury (AKI) remains a significant challenge. Animal studies presented causal links between elevated regulatory T cell (Treg) response and better prognosis in AKI. Previous studies in mice and humans showed that TIM-3+ Treg cells were more potent than TIM-3- Treg cells. In this study, we investigated the role of TIM-3 in Treg in AKI patients.

METHODS

Peripheral blood from AKI patients and healthy controls were gathered, and TIM-3+ Treg subset was examined.

RESULTS

Compared to healthy controls, the AKI patients presented a significant upregulation in the frequency of circulating CD4+CD25+ T cells; however, the majority of this increase was from the CD4+CD25+TIM-3- subset, and the frequency of CD4+CD25+TIM-3+ T cells was downregulated in AKI patients. In both healthy controls and AKI patients, the CD4+CD25+TIM-3+ T cells expressed higher levels of Foxp3, and were more potent at expressing LFA-1, LAG-3, CTLA-4, IL-10 and TGF-β. In addition, the CD4+CD25+TIM-3+ T cells from both healthy controls and AKI patients presented higher capacity to suppress CD4+CD25- T cell proliferation than the CD4+CD25+TIM-3- T cells. Interestingly, the total CD4+CD25+ T cells from AKI patients presented significantly lower inhibitory capacity than those from healthy controls, indicating that the low frequency of CD4+CD25+TIM-3+ T cells was restricting the efficacy of the Treg responses in AKI patients.

CONCLUSIONS

We demonstrated that TIM-3 downregulation impaired the function of Treg cells in AKI. The therapeutic potential of CD4+CD25+TIM-3+ T cells in AKI should be investigated in future studies.

Investigation of gel formation and volatilization of acetate acid in magnesium acetate droplets by the optical tweezers

Hygroscopicity and volatility of single magnesium acetate (MgAc₂) aerosol particles at various relative humidities (RHs) are studied by a single-beam optical tweezers, and refractive indices (RIs) and morphology are characterized by cavity enhanced Raman spectroscopy. Gel formation and volatilization of acetate acid (HAc) in MgAc₂ droplets are observed. Due to the formation of amorphous gel structure, water transposition in droplets at RH < 50% is significantly impeded on a time scale of 140,000 s. Different phase transition at RH < 10% is proposed to explain the distinct water loss after the gel formation. To compare volatilization of HAc in different systems, MgAc₂ and sodium acetate (NaAc) droplets are maintained at several different stable RHs during up to 86,000 s. At RH ≈ 74%, magnesium hydroxide (Mg(OH)₂) inclusions are formed in MgAc₂ droplets due to the volatilization of HAc, and whispering gallery modes (WGMs) of MgAc₂ droplets in the Raman spectrum quench after 50,000 s. In sharp contrast, after 86,000 s at RH ≈ 70%, NaAc droplets are in well-mixed liquid states, containing soluble sodium hydroxide (NaOH). At this state, the RI of NaAc droplet is increased, and the quenching of WGMs is not observable.

Trends in drug-resistant tuberculosis in China: data from a clinical tuberculosis centre

OBJECTIVE

To describe the trends in prevalence of drug-resistant tuberculosis (TB) among in-patients in Beijing Chest Hospital, Beijing, China, using a 10-year retrospective study.

DESIGN

From 2005 to 2014, 18 310 in-patients with TB were recruited for the study, most of whom were referrals; no distinction was made between new and previously treated cases. Drug susceptibility testing (DST) was performed in culture-positive cases using the proportion method to determine multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Risk factors associated with drug resistance were identified.

RESULTS

A total of 5141 (28.0%) samples were culture-positive. DST results showed that 860 (16.7%) cases were MDR-TB and 176 (3.4%) were XDR-TB. MDR-TB and XDR-TB were detected in respectively 21.2% and 12.5% of new cases. The rate of MDR-TB and XDR-TB gradually increased from 2005, with MDR-TB reaching a peak in 2008 and XDR-TB in 2009. These data closely mirror national survey data on this region, patient age and occupation.

CONCLUSION

Trends in MDR-TB and XDR-TB prevalence during the past decade and their inflection points were determined, which complemented reports from previous national surveys. This information is useful for fighting TB in China.

Different clusters of Candidatus 'Methanoperedens nitroreducens'-like archaea as revealed by high-throughput sequencing with new primers

The newly discovered Candidatus ‘Methanoperedens nitroreducens’ (M. nitroreducens), mediating nitrate-dependent anaerobic oxidation of methane, is an important microorganism in linking carbon and nitrogen cycles. In order to explore the diversity of M. nitroreducens-like archaea in various environmental niches with advanced high-throughput sequencing, new primers based on alpha subunit of methyl-coenzyme M reductase gene were designed. The PCR results demonstrated that the new primers could effectively detect M. nitroreducens-like archaea from an enrichment culture dominated by M. nitroreducens as well as samples collected from a natural freshwater lake and a full-scale wastewater treatment plant (WWTP). By high-throughput sequencing, more than 30,000 M. nitroreducens-like sequences were obtained. Phylogenetic analysis of these sequences along with published sequences showed that M. nitroreducens-like archaea could be divided into three sub-branches (named as Group A, Group B and Group C in this study). Clear geographical difference was observed, with Group A and Group B dominating samples in Queensland (Australia) and in European ecosystems, respectively. Further quantitative PCR revealed that the M. nitroreducens-like archaea were more abundant in WWTP than the freshwater lake. The study provided a large number of sequences for M. nitroreducens-like archaeal communities, thus expanded our understanding on the ecological diversity of M. nitroreducens-like archaea.

Tuning the spectral response of ultraviolet organic-inorganic hybrid photodetectors via charge trapping and charge collection narrowing

Organic-inorganic hybrid ultraviolet photodetectors with tunable spectral response are desirable for many different applications. In this work, we blended poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) with ZnO nanoparticles in weight ratios of 1 : 1 and 2 : 1 to create charge traps within the active layers for devices with the conventional structure ITO/PEDOT : PSS/PTAA : ZnO/BCP/Al. Thin (150-200 nm) and thick (1400-1900 nm) active layers were employed to utilize charge collection narrowing (CCN). Both thickness and composition of the active layer impacted the spectral tunability of the photoresponse. A single narrow response peak centered at 420 nm (the PTAA absorption edge) with a full width at half maximum of 12 nm was achieved from the device with a 1900 nm active layer and PTAA : ZnO weight ratio of 1 : 1. Decreasing the active layer thickness to 150 nm resulted in a broad spectral response between 320-420 nm with an external quantum efficiency (EQE) value of 295% under 350 nm illumination and a -1 V bias, exhibiting photomultiplication via charge trapping and injection even at small reverse biases. Increasing the weight ratio of PTAA : ZnO to 2 : 1 lowered both the dark current and photocurrent, eliminated photomultiplication in the thin device, and diminished the efficacy of CCN to narrow the spectral photoresponse in the thick device. Transfer matrix method (TMM) and 3-dimensional finite-difference time-domain (3D-FDTD) simulations were performed to understand the impact of thickness and composition of the active layer on the spectral response of UV photodetectors in terms of exciton generation rate and electric field distribution within the devices.