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Systemic Hypertension (HTN) accounts for the largest amount of attributable Cardiovascular (CV) mortality worldwide. There are several factors responsible for the development of HTN and its CV complications. Multicenter trials revealed that risk factors responsible for Micro Vascular Disease (MVD) are similar for those attributable to Coronary Artery Disease (CAD) which include tobacco use, unhealthy cholesterol levels, HTN, obesity and overweight, physical inactivity, unhealthy diet, diabetes, insulin resistance, increasing age and genetic predisposition. In addition, the defective release of Nitric Oxide (NO) could be a putative candidate for HTN and MVD. This study reviewed the risk stratification of hypertensive population employing cardiac imaging modalities which are of crucial importance in diagnosis. It further emphasized the proper used of cardiac imaging to determine patients at increased CV risk and identify the management strategy. It is now known that NO has an important eff ect on blood pressure, and the basal release of endothelial Nitric Oxide (eNOS) in HTN may be reduced. Although there are diff erent forms of eNOS gene allele, there is no solid data revealing the potential role of the polymorphism of the eNOS in patients with HTN and coronary vascular diseases. In the present article, the prevalence of eNOS G298 allele in hypertensive patients with micro vascular angina will be demonstrated.\ud This review provides an update on appropriate and justified use of non-invasive imaging tests in hypertensive patients and its\ud important role in proper diagnosis of MVD and CAD. Second, eNOS gene allele and its relation to essential hypertension and angina pectoris are also highlighted.

Casting of a donor:acceptor bulk-heterojunction structure from a single ink has been the predominant fabrication method of organic photovoltaics (OPVs). Despite the success of such bulk heterojunctions, the task ofcontrolling the microstructure in a single casting process has been arduous and alternative approaches are desired. To achieve OPVs with a desirable microstructure, a facile and eco-compatible sequential deposition approach is demonstrated for polymer/small-molecule pairs. Using a nominally amorphous polymer as the model material, the profound influence of casting solvent is shown on the molecular ordering of the film, and thus the device performance and mesoscale morphology of sequentially deposited OPVs can be tuned. Static and in situ X-ray scattering indicate that applying (R)-(+)-limonene is able to greatly promote the molecular order of weakly crystalline polymers and form the largest domain spacing exclusively, which correlates well with the best efficiency of 12.5% in sequentially deposited devices. The sequentially cast device generally outperforms its control device based on traditional single-ink bulk-heterojunction structure. More crucially, a simple polymer:solvent interaction parameter χ is positively correlated with domain spacing in these sequentially deposited devices. These findings shed light on innovative approaches to rationally create environmentally friendly and highly efficient electronics.

Intra‐ and intermolecular ordering greatly impacts the electronic and optoelectronic properties of semiconducting polymers. The interrelationship between ordering of alkyl sidechains and conjugated backbones has yet to be fully detailed, despite much prior effort. Here, the discovery of a highly ordered alkyl sidechain phase in six representative semiconducting polymers, determined from distinct spectroscopic and diffraction signatures, is reported. The sidechain ordering exhibits unusually large coherence lengths (≥70 nm), induces torsional/twisting backbone disorder, and results in a vertically multilayered nanostructure with ordered sidechain layers alternating with disordered backbone layers. Calorimetry and in situ variable temperature scattering measurements in a model system poly{4‐(5‐(4,8‐bis(3‐butylnonyl)‐6‐methylbenzo[1,2‐b:4,5‐b′]dithiophen‐2‐yl)thiophen‐2‐yl)‐2‐(2‐butyloctyl)‐5,6‐difluoro‐7‐(5‐methylthiophen‐2‐yl)‐2H‐benzo[d][1,2,3]triazole} (PBnDT‐FTAZ) clearly delineate this competition of ordering that prevents simultaneous long‐range order of both moieties. The long‐range sidechain ordering can be exploited as a transient state to fabricate PBnDT‐FTAZ films with an atypical edge‐on texture and 2.5× improved field‐effect transistor mobility. The observed influence of ordering between the moieties implies that improved molecular design can produce synergistic rather than destructive ordering effects. Given the large sidechain coherence lengths observed, such synergistic ordering should greatly improve the coherence length of backbone ordering and thereby improve electronic and optoelectronic properties such as charge transport and exciton diffusion lengths.

Although non-fullerene small molecular acceptors (NF-SMAs) are dominating current research in organic solar cells (OSCs), measurements of thermodynamics drivers and kinetic factors determining their morphological stability are lacking. Here, we delineate and measure such factors in crystallizable NF-SMA blends and discuss four model systems with respect to their meta-stability and degree of vitrification. We determine for the first time the amorphous-amorphous phase diagram in an NF-SMA system and show that its deep quench depth can result in severe burn-in degradation. We estimate the relative phase behavior of four other materials systems. Additionally, we derive room-temperature diffusion coefficients and conclude that the morphology needs to be stabilized by vitrification corresponding to diffusion constants below 10−22 cm2/s. Our results show that to achieve stability via rational molecular design, the thermodynamics, glass transition temperature, diffusion properties, and related structure-function relations need to be more extensively studied and understood. In recent years, the performance of organic solar cells (OSCs) has greatly improved with the development of novel non-fullerene small molecular acceptors (NF-SMA). The rapid increase in power conversion efficiency, now surpassing 15%, highlights an immediate and increasing need to understand the longevity and lifetime of NF-OSCs. However, the field relies mainly on a laborious trial-and-error approach to select polymer:NF-SMA pairs with desirable device stability. Here, we provide a structure-property relation that explains the morphological stability and burn-in degradation due to excessive demixing or crystallization. The framework presented in our study shows that a specific balance of interactions between polymer and NF-SMA can offer a short-term solution against excessive demixing. Long-term morphological stability that also suppresses crystallization can only be achieved by freezing in the initial quenched morphology through the use of polymers and/or NF-SMAs with low flexibility. This research provides a structure-property relation that sheds light on morphological stability of NF-OSCs by using the thermodynamic and the kinetic perspectives. We show that NF-OSCs can suffer from excessive amorphous-amorphous phase separation in the blends and crystallization of NF-SMA. The former instability channel can be eliminated in systems with an optimal miscibility, whereas the excessive phase separation in low miscibility systems and NF-SMA crystallization need to be suppressed through the utilization of polymers or NF-SMAs with low flexibility.

Several recent reports have demonstrated that fluorinated analogues of donor/acceptor copolymers surpass nonfluorinated counterparts in terms of performance in electronic devices. Using a copolymer series consisting of fluorinated, partially fluorinated, and nonfluorinated benzotriazole, we confirm that the addition of fluorine substituents beneficially impacts charge transport in polymer semiconductors. Transistor measurements demonstrated a factor of 5 increase in carrier mobilities with the degree of fluorination of the backbone. Furthermore, grazing-incidence X-ray diffraction data indicates progressively closer packing between the conjugated cores and an overall greater amount of π-stacking in the fluorinated materials. It is likely that attractive interactions between the electron-rich donor and fluorinated electron-deficient acceptor units induce very tightly stacking crystallites, which reduce the energetic barrier for charge hopping. In addition, a change in crystallite orientation was observed from primarily edge-on without fluorine substituents to mostly face-on with fluorinated benzotriazole.

We review the Stille coupling synthesis of P-(DPP2OD-T) (Poly[[2,5-di(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-3,6-diyl]-alt-[2,2′:5′,2″-terthiophene-5,5″-diyl]]) and show that high-quality, high molecular weight polymer chains are already obtained after as little as 15 min of reaction time. The results of UV−vis spectroscopy, grazing incidence wide-angle X-ray scattering (GIWAXS), and atomic force microscopy show that longer reaction times are unnecessary and do not produce any improvement in film quality. We achieve the best charge transport properties with polymer batches obtained from short reaction times and demonstrate that the catalyst washing step is responsible for the introduction of charge-trapping sites for both holes and electrons. These trap sites decrease the charge injection efficiency, strongly reducing the measured currents. The careful tuning of the synthesis allows us to reduce the reaction time by more than 100 times, achieving a more environmentally friendly, less costly process that leads to high and balanced hole and electron transport, the latter being the best reported for an isotropic, spin-coated DPP polymer.

Fluorinated conjugated polymers leading to enhanced photovoltaic device performance has been widely observed in a variety of donor-acceptor copolymers; however, almost all these polymers have fluorine substituents on the acceptor unit. Building upon our previously reported PBnDT-FTAZ, a fluorinated donor-acceptor conjugated polymer with impressive device performance, we set this study to explore the effect of adding the fluorine substituents onto the flanking thiophene units between the donor unit (BnDT) and the acceptor unit (TAZ). We developed new synthetic approaches to control the position of the fluorination (3′ or 4′) on the thiophene unit, and synthesized four additional PBnDT-TAZ polymers incorporating the fluorine-substituted-thiophene (FT) units, 3′-FT-HTAZ, 4′-FT-HTAZ, 3′-FT-FTAZ, and 4′-FT-FTAZ. We discover that relocating the fluorine substituents from the acceptor to the flanking thiophene units have a negligible impact on the device characteristics (short circuit current, open circuit voltage, and fill factor) when comparing 4′-FT-HTAZ with the original FTAZ. Combining these two fluorination approaches together, 4′-FT-FTAZ shows even higher device performance than FTAZ (7.7% vs 6.6%) with active layers over 200 nm in thickness. Furthermore, high values of fill factor∼70% are all achieved for photovoltaic devices based on 3′-FT-HTAZ, 4′-FT-HTAZ, or 4′-FT-FTAZ, ascribed to the observed high hole mobilities (over 1 × 10-3 cm2/(V s)) in these devices. Our study offers a new approach to utilize the fluorinated thiophene units in developing new conjugated polymers to further improve the device performance of polymer solar cells.