Pars Plana Vitrectomy With Silicone Oil or Gas Tamponade for Uncomplicated Retinal Detachment: A Systematic Review and Meta-Analysis.

PURPOSE: To compare the efficacy and safety of pars plana vitrectomy (PPV) with silicone oil compared to gas tamponade for uncomplicated rhegmatogenous retinal detachment (RRD). DESIGN: Systematic review and meta-analysis. METHODS: A systematic literature search was conducted on Ovid MEDLINE, Embase, and the Cochrane Library from January 2000 to September 2023 for comparative studies evaluating the efficacy and safety of PPV with either silicone oil or gas tamponade in the setting of uncomplicated RRD. Our primary outcome was best-corrected visual acuity at the last study observation. Secondary outcomes included the rates of retinal reattachment, retinal thickness, and the incidence of adverse events. We performed a meta-analysis using a random-effects model. RESULTS: Nine observational studies reporting on 491 RRD eyes were included. The mean best-corrected visual acuity at the last study observation was significantly better in the gas tamponade group than in the silicone oil group (weighted mean difference [WMD] = 0.17 logMAR, 95% confidence interval [CI] = [0.06, 0.27], P = .002). Rates of primary retinal reattachment were similar between the silicone oil and gas tamponade groups (P = .89). The ganglion cell layer was significantly thinner in the silicone oil group compared to the gas tamponade group (WMD =-3.70 µm, 95% CI = [-5.87, -1.53, P = .0008), as was the inner plexiform layer (WMD = -2.45, 95% CI = [-4.50, -0.40], P = .02) and outer nuclear layer (WMD = -11.74 µm, 95% CI = [-18.39, -5.10], P = .0005). CONCLUSIONS: PPV with gas tamponade was associated with better functional outcomes compared to PPV with silicone oil, although both tamponades yielded comparable primary reattachment rates. The absence of randomized trials and the potential for selection bias underscore the importance of further investigation in diverse patient populations.

Antiviral and Antibacterial 3D-Printed Products Functionalised with Poly(hexamethylene biguanide).

Infection prevention and public health are a vital concern worldwide, especially during pandemics such as COVID-19 and seasonal influenza. Frequent manual disinfection and use of chemical spray coatings at public facilities are the typical measures taken to protect people from coronaviruses and other pathogens. However, limitations of human resources and coating durability, as well as the safety of disinfectants used are the major concerns in society during a pandemic. Non-leachable antimicrobial agent poly(hexamethylene biguanide) (PHMB) was mixed into photocurable liquid resins to produce novel and tailor-made covers for public facilities via digital light processing, which is a popular 3D printing technique for satisfactory printing resolution. Potent efficacies of the 3D-printed plastics were achieved in standard antibacterial assessments against S. aureus, E. coli and K. pneumoniae. A total of 99.9% of Human coronavirus 229E was killed after being in contact with the 3D-printed samples (containing the promising PHMB formulation) for two hours. In an eight-week field test in Hong Kong Wetland Park, antibacterial performances of the specially designed 3D-printed covers analysed by environmental swabbing were also found to be satisfactory. With these remarkable outcomes, antimicrobial products prepared by digital light processing 3D printing can be regarded as a reliable solution to long-term infection prevention and control.

A timely and accurate approach to nearshore oil spill monitoring using deep learning and GIS.

Oil spill accidents are a key contributor to marine pollution worldwide. Therefore, timely and effective oil spill detection is crucial for reducing marine pollution and enhancing environmental protection. Against this backdrop, this study explored two methods for performing nearshore on-site oil spill detection and segmentation, namely the U-net and Mask region-based convolutional neural network (R-CNN) methods. The U-net and Mask R-CNN models were revealed to exhibit acceptable and favorable performance, achieving overall accuracy of 77.01 % and 89.02 %, respectively. Subsequently, a verification system based on the Geographic Information System (GIS) was developed to improve the performance of the deep-learning model. With the integration of the verification system, the Mask R-CNN model achieved higher overall accuracy of 90.78 %. The feasibility of applying deep-learning methods to nearshore on-site oil spill monitoring was demonstrated through this study. In addition, the integration of the GIS not only assisted in the provision of oil spill information but also in the improvement of the deep-learning models. The timely, accurate, and effective method for nearshore on-site oil spill monitoring that this study explored can be applied to considerably improve traditional on-site oil spill monitoring, which has received limited academic attention in the last two decades.

Global Comparison of Readmission Rates for Patients With Heart Failure.

BACKGROUND: Heart failure (HF) readmission rates are low in some jurisdictions. However, international comparisons are lacking and could serve as a foundation for identifying regional patient management strategies that could be shared to improve outcomes. OBJECTIVES: This study sought to summarize 30-day and 1-year all-cause readmission and mortality rates of hospitalized HF patients across countries and to explore potential differences in rates globally. METHODS: We performed a systematic review and meta-analysis using MEDLINE, Embase, and CENTRAL for observational reports on hospitalized adult HF patients at risk for readmission or mortality published between January 2010 and March 2021. We conducted a meta-analysis of proportions using a random-effects model, and sources of heterogeneity were evaluated with meta-regression. RESULTS: In total, 24 papers reporting on 30-day and 23 papers on 1-year readmission were included. Of the 1.5 million individuals at risk, 13.2% (95% CI: 10.5%-16.1%) were readmitted within 30 days and 35.7% (95% CI: 27.1%-44.9%) within 1 year. A total of 33 papers reported on 30-day and 45 papers on 1-year mortality. Of the 1.5 million individuals hospitalized for HF, 7.6% (95% CI: 6.1%-9.3%) died within 30 days and 23.3% (95% CI: 20.8%-25.9%) died within 1 year. Substantial variation in risk across countries was unexplained by countries' gross domestic product, proportion of gross domestic product spent on health care, and Gini coefficient. CONCLUSIONS: Globally, hospitalized HF patients exhibit high rates of readmission and mortality, and the variability in readmission rates was not explained by health care expenditure, risk of mortality, or comorbidities.

Whole-Genome Duplication and Genome Instability in Cancer Cells: Double the Trouble.

Whole-genome duplication (WGD) is one of the most common genomic abnormalities in cancers. WGD can provide a source of redundant genes to buffer the deleterious effect of somatic alterations and facilitate clonal evolution in cancer cells. The extra DNA and centrosome burden after WGD is associated with an elevation of genome instability. Causes of genome instability are multifaceted and occur throughout the cell cycle. Among these are DNA damage caused by the abortive mitosis that initially triggers tetraploidization, replication stress and DNA damage associated with an enlarged genome, and chromosomal instability during the subsequent mitosis in the presence of extra centrosomes and altered spindle morphology. Here, we chronicle the events after WGD, from tetraploidization instigated by abortive mitosis including mitotic slippage and cytokinesis failure to the replication of the tetraploid genome, and finally, to the mitosis in the presence of supernumerary centrosomes. A recurring theme is the ability of some cancer cells to overcome the obstacles in place for preventing WGD. The underlying mechanisms range from the attenuation of the p53-dependent G1 checkpoint to enabling pseudobipolar spindle formation via the clustering of supernumerary centrosomes. These survival tactics and the resulting genome instability confer a subset of polyploid cancer cells proliferative advantage over their diploid counterparts and the development of therapeutic resistance.

Outcomes of Arterial Bypass for Posterior Circulation Atherosclerosis: A Case Series.

BACKGROUND: Extracranial-intracranial bypass is an effective treatment option for moyamoya disease and in well-selected cases of anterior circulation intracranial atherosclerotic disease; however, the effectiveness of bypass is less evident in posterior circulation atherosclerosis. Updated surgical techniques and clinical guidelines necessitate modern appraisal of arterial bypass for symptomatic patients with posterior circulation atherosclerotic disease who are refractory to medical management. OBJECTIVE: To evaluate the complications, graft patency, and postoperative outcomes of arterial bypass for posterior circulation intracranial atherosclerotic disease. METHODS: Perioperative records of consecutive bypass patients were retrospectively evaluated to determine the clinical course and surgical outcomes. RESULTS: Arterial bypass was performed in 8 cases with a median age of 62 years. All 8 patients underwent direct bypass with an autologous occipital artery donor vessel. Recipient vessel selection varied on a case-by-case basis, with the superior cerebellar artery used in 4 cases, the posterior inferior cerebellar artery in 3 cases, and the anterior inferior cerebellar artery in 1 case. There were no significant intraoperative or postoperative complications. Postoperatively, all 8 patients displayed clinical improvement of their preoperative symptoms, with a significant decrease of 2.5 points on the modified Rankin Scale (P < .001). Postoperative imaging confirmed full graft patency in 7 patients and partial patency in 1 patient. CONCLUSION: Excellent postoperative outcomes and no major complications after posterior circulation arterial bypass for intracranial atherosclerotic disease highlight the utility of this intervention for the treatment of medically refractory or symptomatic posterior circulation intracranial atherosclerotic disease. Larger studies may be valuable to validate these findings.

Transcarotid artery revascularization (TCAR) stenting or angioplasty for intracranial carotid artery stenosis: Case series and novel application.

BACKGROUND: Carotid artery stenting is associated with a higher rate of stroke compared to carotid endarterectomy (CEA). This is likely due to procedural emboli resulting from plaque disruption. The transcarotid artery revascularization (TCAR) method aims to reduce the stroke rate by flow-reversal. TCAR, which has yet to be utilized for intracranial atherosclerotic disease (ICAD), may be particularly valuable given the lack of surgical treatment options for intracranial arterial stenosis. OBJECTIVE: Presented here are five cases of angioplasty or stenting that demonstrate the feasibility of TCAR for intracranial Internal Carotid Artery (ICA) stenosis treatment. METHODS: Five cases were reviewed retrospectively and summarized using PROCESS and CARE guidelines. RESULTS: All patients who underwent intervention between the petrous and ophthalmic segment of the ICA had no new neurologic deficit nor detected embolic stroke. One patient experienced an asymptomatic 5 mm hemorrhage on postoperative routine Computed Tomography (CT) head imaging. CONCLUSIONS: This highlights a new method for treating intracranial ICA stenosis with a potentially reduced stroke risk. Given the historically higher stroke rates for cervical ICA stenting compared to carotid artery endarterectomy, this method may improve the previously higher stroke rates in endovascular carotid artery treatment, compared to CEA. Although this series is small, it illustrates a novel use for a rising technique that should be further evaluated in a larger study to validate its efficacy as a new treatment modality for surgically inaccessible intracranial disease.

Robotic Arm-Protected Microsurgical Pericallosal and Middle Cerebral Artery Aneurysm Clipping: A Technical Note and Case Series.

BACKGROUND: Managing intraoperative aneurysm rupture (IAR) during intracranial aneurysm clipping can be challenging given the excessive hemorrhage and limited field of view under the microscope for visualizing the proximal artery and safe temporary clipping. OBJECTIVE: To describe the first known use of robotic arm for safeguarding IAR in microsurgical aneurysm clipping. METHODS: A robotic arm was used to safeguard 3 microsurgical clipping cases (1 pericallosal and 2 middle cerebral artery) performed by a single surgeon. The device was installed onto the side rail of the operating table along with the clip applier attachment. After dissecting the cerebral artery segment proximal to the aneurysm, a temporary aneurysm clip was loaded and established at the appropriate segment before dissecting distally toward the aneurysm. RESULTS: Setup for the robotic arm and temporary clip was simple, quick, precise, and without any unforeseen accommodations needed in all 3 instances. The temporary clip acted as an emergency gate and could be deployed either manually or remotely through a controller. IAR occurred in case 1, and the robotic-assisted temporary clip deployment achieved immediate hemostasis without complications. This method bypassed the need for significant suctioning, packing, and further exploration for safe temporary clipping. Case 2 and 3 demonstrated the feasibility for middle cerebral artery protection and ease of intraoperative readjustment. CONCLUSION: This technical note highlights the feasibility and relative ease of using a robotic arm as a safeguard device, and it enables on-demand control of proximal blood flow and may enhance the safety of microsurgical aneurysm procedures.

A flow self-regulating superficial temporal artery-middle cerebral artery bypass based on side-to-side anastomosis for adult patients with moyamoya disease.

OBJECTIVE: Side-to-side (S-S) superficial temporal artery-middle cerebral artery (STA-MCA) bypass was reportedly used to treat a special moyamoya disease (MMD) patient with collaterals arising from the donor STA. However, the S-S technique is not routinely performed to date, and its benefits are still unknown for adult MMD. The purpose of this study was to investigate the possibility of routine use of the S-S technique for adult MMD. METHODS: The authors retrospectively analyzed the clinical data of 50 adult patients (65 hemispheres, including 30 in the end-to-side [E-S] group and 35 in the S-S group) with MMD who underwent STA-MCA bypass. The patient demographic characteristics, clinical courses, technical details, intraoperative blood flow data, postoperative and preoperative relative cerebral blood flow (rCBF) values, modified Rankin Scale (mRS) scores, and short-term revascularization results were compared between the 2 groups. RESULTS: There were no significant differences observed in terms of the baseline characteristics, bypass patency rates, postoperative/preoperative rCBF values, incidence of cerebral hyperperfusion syndrome (CHS), mRS scores, and short-term revascularization results between the 2 groups (all p > 0.05). Intraoperative blood flow analysis showed that the increase of STA flow in the E-S group was significantly higher than that of proximal STA flow in the S-S group (p = 0.008). Although the increases of proximal and distal recipient flow in the E-S group seemed greater than those in the S-S group, the results were not statistically significant (p = 0.086 for proximal flow and p = 0.076 for distal flow). CHS symptoms in the S-S group were milder and with much shorter duration. The follow-up angiographic data of the representative case demonstrated that both frontal and parietal STA branches and the occipital artery participated in postoperative collateralization. CONCLUSIONS: S-S anastomosis can achieve comparable clinical effects to standard E-S construction. S-S anastomosis used in adult MMD demonstrated mild CHS symptoms with short duration and had the potential to arouse all scalp arteries as donor sources for revascularization through the intact distal STA branch via flow self-regulation.

Scleral-fixated and iris-fixated intraocular lens implantation or fixation:meta-analysis.

Scleral fixation and iris fixation are common intraocular lens (IOL) implantation techniques performed because of zonulopathy. There is a lack of consensus regarding their comparative efficacy and safety. This study aims to compare the efficacy and safety outcomes after scleral-fixated (SF) vs iris-fixated (IF) IOL implantation or fixation in adults. A systematic literature search was conducted on Ovid MEDLINE, Embase, and Cochrane CENTRAL from 2005 to 2020. 785 eyes from 2 randomized controlled trials and 9 nonrandomized studies were included. There was no significant difference in the mean corrected distance visual acuity at the final follow-up ( P = .52) or absolute change in spherical equivalent ( P = .88) between SF IOL and IF IOL implantation. The incidence of vitreous hemorrhage was significantly higher in the SF IOL group (risk ratio = 3.66, 95% CI, 1.16-11.55, P = .03). There were no differences in visual acuity and refractive outcomes between SF IOL and IF IOL implantation or fixation. Trade-offs in complications exist between the 2 techniques.

Fucoxanthin Is a Potential Therapeutic Agent for the Treatment of Breast Cancer.

Breast cancer (BC) is one of the most common cancers diagnosed and the leading cause of cancer-related death in women. Although there are first-line treatments for BC, drug resistances and adverse events have been reported. Given the incidence of BC keeps increasing, seeking novel therapeutics is urgently needed. Fucoxanthin (Fx) is a dietary carotenoid commonly found in seaweeds and diatoms. Both in vitro and in vivo studies show that Fx and its deacetylated metabolite fucoxanthinol (Fxol) inhibit and prevent BC growth. The NF-κB signaling pathway is considered the major pathway contributing to the anti-proliferation, anti-angiogenesis and pro-apoptotic effects of Fx and Fxol. Other signaling molecules such as MAPK, MMP2/9, CYP and ROS are also involved in the anti-cancer effects by regulating the tumor microenvironment, cancer metastasis, carcinogen metabolism and oxidation. Besides, Fx also possesses anti-obesity effects by regulating UCP1 levels and lipid metabolism, which may help to reduce BC risk. More importantly, mounting evidence demonstrates that Fx overcomes drug resistance. This review aims to give an updated summary of the anti-cancer effects of Fx and summarize the underlying mechanisms of action, which will provide novel strategies for the development of Fx as an anti-cancer therapeutic agent.

Modern Appraisal of Patency and Complications in Cerebral Bypass Surgery: A Single Institution Experience.

BACKGROUND: Cerebral bypass is a valuable surgical technique in well-selected patient populations. Updated clinical guidelines and improved surgical techniques warrant a contemporary reevaluation of the complications and patency to inform clinical practice and enhance postoperative patient care. OBJECTIVE: To assess the complication rates and postoperative graft patency for the 3 most common indications for bypass surgery: moyamoya disease, intracranial atherosclerosis, and intracranial aneurysms. METHODS: Perioperative notes of 175 consecutive bypass patients at a single institution were retrospectively identified to evaluate the clinical course and complications of surgery. RESULTS: The rate of total postoperative complications between moyamoya disease (9 of 98, 9.2%), intracranial atherosclerotic disease (7 of 57, 12.3%), and intracranial aneurysm (4 of 20, 20%) was not statistically different (P = .33). Immediate postoperative bypass patency was significantly higher in moyamoya disease (90 of 96, 93.8%) and intracranial atherosclerotic disease (48 of 51, 94.1%) than in intracranial aneurysm (13 of 18, 72.2%; P = .02). Intravenous heparin administration during bypass suturing was negatively associated with immediate postoperative patency (87% heparin patency vs 99% no heparin patency; P = .02). Double-barrel bypass trended toward an increased risk of wound healing complications (2 of 13, 15.4%) compared with the single-barrel bypass technique (4 of 156, 2.6%; P = .07). CONCLUSION: Cerebral bypass surgery remains an excellent surgical treatment for moyamoya disease, intracranial atherosclerosis, and intracranial aneurysms. This study suggests bypass is safer in moyamoya disease and intracranial atherosclerosis. Additional studies to clarify the risk of single-barrel vs double-barrel bypass and intraoperative heparin-stratified complications may be beneficial.

Sutured Scleral-Fixated Versus Anterior Chamber Intraocular Lens Implantation: A Meta-Analysis.

BACKGROUND AND OBJECTIVE: No consensus exists on the comparative efficacy and safety of sutured scleral-fixated (SSF) and anterior chamber (AC) intraocular lens (IOL) implantation. We aim to compare outcomes of these two techniques. PATIENTS AND METHODS: A systematic literature search of MEDLINE, Embase, and Cochrane CENTRAL was conducted (2005 to 2020). Studies comparing SSFIOLs with ACIOLs were included. Outcomes included corrected distance visual acuity and complications. A meta-analysis was conducted with a random effects model. Weighted mean differences and risk ratios with 95% CIs were computed. RESULTS: Seven hundred eighty-three eyes from nine studies were included. SSFIOLs had a significantly higher absolute postoperative spherical equivalent (weighted mean difference, 0.32; 95% CI, 0.03 to 0.60; P = .03; low certainty) and incidence of IOL decentration/subluxation (risk ratio, 2.69; 95% CI, 1.03 to 7.01; P = .04; moderate certainty) than ACIOLs. There was no difference in final corrected distance visual acuity (P = .26). CONCLUSIONS: SSFIOLs have a higher absolute postoperative spherical equivalent and incidence of IOL decentration/subluxation than ACIOLs. Future prospective studies are needed to confirm these findings. [Ophthalmic Surg Lasers Imaging Retina. 2022;53:12-21.].

Uncovering the out-of-plane nanomorphology of organic photovoltaic bulk heterojunction by GTSAXS.

The bulk morphology of the active layer of organic solar cells (OSCs) is known to be crucial to the device performance. The thin film device structure breaks the symmetry into the in-plane direction and out-of-plane direction with respect to the substrate, leading to an intrinsic anisotropy in the bulk morphology. However, the characterization of out-of-plane nanomorphology within the active layer remains a grand challenge. Here, we utilized an X-ray scattering technique, Grazing-incident Transmission Small-angle X-ray Scattering (GTSAXS), to uncover this new morphology dimension. This technique was implemented on the model systems based on fullerene derivative (P3HT:PC71BM) and non-fullerene systems (PBDBT:ITIC, PM6:Y6), which demonstrated the successful extraction of the quantitative out-of-plane acceptor domain size of OSC systems. The detected in-plane and out-of-plane domain sizes show strong correlations with the device performance, particularly in terms of exciton dissociation and charge transfer. With the help of GTSAXS, one could obtain a more fundamental perception about the three-dimensional nanomorphology and new angles for morphology control strategies towards highly efficient photovoltaic devices.

Molecular insights of exceptionally photostable electron acceptors for organic photovoltaics.

Photo-degradation of organic semiconductors remains as an obstacle preventing their durable practice in optoelectronics. Herein, we disclose that volume-conserving photoisomerization of a unique series of acceptor-donor-acceptor (A-D-A) non-fullerene acceptors (NFAs) acts as a surrogate towards their subsequent photochemical reaction. Among A-D-A NFAs with fused, semi-fused and non-fused backbones, fully non-fused PTIC, representing one of rare existing samples, exhibits not only excellent photochemical tolerance in aerobic condition, but also efficient performance in solar cells. Along with a series of in-depth investigations, we identify that the structural confinement to inhibit photoisomerization of these unique A-D-A NFAs from molecular level to macroscopic condensed solid helps enhancing the photochemical stabilities of molecules, as well as the corresponding OSCs. Although other reasons associating with the photostabilities of molecules and devices should not excluded, we believe this work provides helpful structure-property information toward new design of stable and efficient photovoltaic molecules and solar cells.

Gender differences in externalizing and internalizing problems in Singaporean children and adolescents with attention-deficit/hyperactivity disorder.

BACKGROUND: Studies on gender differences in attention-deficit/hyperactivity disorder (ADHD) comorbidities in the Asian populations have been limited and previous studies have shown inconclusive findings. Singapore is a city-state country in Southeast Asia with a population of 5.7 million. This study examined gender differences in internalizing and externalizing problems in Singaporean children and adolescents with ADHD. The plausible social factors underlying the gender differences were discussed. METHODS: A total of 773 participants (aged 6 to 18, 88% males) newly diagnosed with ADHD were recruited from the largest public child and adolescent psychiatric center in Singapore. Their internalizing and externalizing problems were assessed using the Child Behavioral Checklist and Teacher's Report Form by parents and teachers respectively. Demographics and relevant social factors were collected using parent questionnaires. RESULTS: Females with ADHD were reported to have less delinquent and aggressive behavior but more depressive symptoms than their male counterparts, similar to findings in the Western literature. Gender remained a significant predictor of externalizing problem after controlling for other factors. Lower socioeconomic status and parental use of physical punishment were significant predictors of both internalizing and externalizing problems. CONCLUSIONS: Gender differences in ADHD comorbidities do exist in the Asian clinical population. The lack of externalizing symptoms in females with ADHD has made timely referral and diagnosis challenging. More research is needed in understanding the gender differences in ADHD and the biopsychosocial mechanism underlying the differences in order to improve the detection of ADHD in females.

Antibiotic-Resistant Bacteria in Hydroponic Lettuce in Retail: A Comparative Survey.

Hydroponic produce is gaining popularity due to its suitability for urban agriculture. The general public also considers that hydroponic produce is free from microbiological contamination. In this study, we compared the frequency and abundance of tetracycline-resistant and sulphadiazine-resistant bacteria and the minimal inhibitory concentration (MIC) of these isolates in conventional, organic, and hydroponic lettuce sold in retail. We also determined the frequency of samples carrying tetB, tetX, sul1, sul2, and int1 genes by PCR and further quantified the copy number of tetX, sul1, and int1 genes in samples positive for these genes using qPCR. As expected, the number of resistant bacteria and the MICs of these isolates were lowest in hydroponic lettuce and highest in organic lettuce. All tested resistant genes, except int1, were detected in samples of all three production methods, but no significant difference was observed between the three groups in the frequency of samples carrying the resistance genes examined or in their copy number. To the best of our knowledge, it is the first study directly reporting the existence of antibiotic-resistant bacteria and resistance genes in hydroponic vegetables sold in retail. The result highlights that the risk of antibiotic-resistant bacteria contamination in hydroponic produce should be further investigated.

Asymmetric Electron Acceptors for High-Efficiency and Low-Energy-Loss Organic Photovoltaics.

Low energy loss and efficient charge separation under small driving forces are the prerequisites for realizing high power conversion efficiency (PCE) in organic photovoltaics (OPVs). Here, a new molecular design of nonfullerene acceptors (NFAs) is proposed to address above two issues simultaneously by introducing asymmetric terminals. Two NFAs, BTP-S1 and BTP-S2, are constructed by introducing halogenated indandione (A1 ) and 3-dicyanomethylene-1-indanone (A2 ) as two different conjugated terminals on the central fused core (D), wherein they share the same backbone as well-known NFA Y6, but at different terminals. Such asymmetric NFAs with A1 -D-A2 structure exhibit superior photovoltaic properties when blended with polymer donor PM6. Energy loss analysis reveals that asymmetric molecule BTP-S2 with six chlorine atoms attached at the terminals enables the corresponding devices to give an outstanding electroluminescence quantum efficiency of 2.3 × 10-2 %, one order of magnitude higher than devices based on symmetric Y6 (4.4 × 10-3 %), thus significantly lowering the nonradiative loss and energy loss of the corresponding devices. Besides, asymmetric BTP-S1 and BTP-S2 with multiple halogen atoms at the terminals exhibit fast hole transfer to the donor PM6. As a result, OPVs based on the PM6:BTP-S2 blend realize a PCE of 16.37%, higher than that (15.79%) of PM6:Y6-based OPVs. A further optimization of the ternary blend (PM6:Y6:BTP-S2) results in a best PCE of 17.43%, which is among the highest efficiencies for single-junction OPVs. This work provides an effective approach to simultaneously lower the energy loss and promote the charge separation of OPVs by molecular design strategy.

Soft Porous Blade Printing of Nonfullerene Organic Solar Cells.

Developing scalable and robust processing methods with low material waste remains a challenge for organic solar cells (OSCs) to become a practical renewable energy source. Here, we present a novel low-cost processing approach termed as soft porous blade printing (SPBP), which uses a layer of soft porous material such as filter paper as the printing blade. The inherent porous microstructure of the blade offers high shear rates that facilitate the alignment, crystallization, and orientation of active materials during printing. Moreover, by eliminating the suspended liquid meniscus, SPBP relaxes the stringent requirement of gap control and enables continuous ink delivery for uninterrupted film fabrication with adjustable thickness. Higher photovoltaic performances are achieved in the SPBP-printed OSCs than those of the spin-coated counterparts for two nonfullerene-acceptor active-layer systems (Y6:PM6 and PTQ10:IDIC). Y6:PM6 cells printed by SPBP without any additive exhibit power conversion efficiencies up to 14.75%, which is among the highest reported to date for non-spin-coated OSCs.