What Triggers the Dynamic Self-Assembly of Molecules and Materials?

Dynamic self-assembly has emerged as one of the reliable approaches to create complex materials with more life-like functions. In a typical dynamic self-assembly process, the external triggers activate the building blocks to initiate the assembly step to form transiently stable higher-order structures. These external triggers provide a constant supply of energy to maintain the transiently stable self-assembled states. The withdrawal or consumption of the trigger deactivates the building block in the aggregates, thereby initiating the disassembly step. A precise control over the interplay between the deterministic and nondeterministic forces is the key to achieving a dynamic self-assembly process. This demands the appropriate choice of building blocks as well as triggers, which has led to the development of a wide range of triggers in dynamic self-assembly. Through this Perspective, we intend to highlight the functional diversities, prospects, and challenges associated with different classes of "triggers" by bringing them under one platform. Such treatment will help us to identify the missing features and deduce a guideline for the development of ideal triggers. A few of the desirable features that a trigger should possess, along with probable ways to achieve them, are discussed, as well. In summary, the Perspective covers many intriguing aspects of triggers that can be helpful for researchers to achieve precise spatiotemporal control over various interparticle interactions, which is essential to obtaining the desired outcome from a dynamic self-assembly process.

Halved contrast medium dose in lower limb dual-energy computed tomography angiography-a randomized controlled trial.

OBJECTIVES: To compare vascular attenuation (VA) of an experimental half iodine-load dual-layer spectral detector CT (SDCT) lower limb computed tomography angiography (CTA) with control (standard iodine-load conventional 120-kilovolt peak (kVp) CTA). METHODS: Ethical approval and consent were obtained. In this parallel RCT, CTA examinations were randomized into experimental or control. Patients received 0.7 vs 1.4 mL/kg of iohexol 350 mgI/mL in the experimental- vs the control group. Two experimental virtual monoenergetic image (VMI) series at 40 and 50 kiloelectron volts (keV) were reconstructed. PRIMARY OUTCOME: VA. SECONDARY OUTCOMES: image noise (noise), contrast- and signal-to-noise ratio (CNR and SNR), and subjective examination quality (SEQ). RESULTS: A total of 106 vs 109 were randomized and 103 vs 108 were analyzed in the experimental vs, control groups, respectively. VA was higher on experimental 40 keV VMI than on control (p < 0.0001), but lower on 50 keV VMI (p < 0.022). Noise was higher on experimental 40 keV VMI than on control (p = 0.00022), but lower on 50 keV VMI (p = 0.0033). CNR and SNR were higher than the control on experimental 40 keV VMI (both p < 0.0001) and 50 keV (p = 0.0058 and p = 0.0023, respectively). SEQ was better on both VMIs in the experimental group than in the control (both p < 0.0001). CONCLUSIONS: Half iodine-load SDCT lower limb CTA at 40 keV achieved higher VA than the control. CNR, SNR, noise, and SEQ were higher at 40 keV, while 50 keV showed lower noise. CLINICAL RELEVANCE STATEMENT: Spectral detector CT with low-energy virtual monoenergetic imaging performed halved iodine contrast medium (CM) lower limb CT-angiography with sustained objective and subjective quality. This facilitates CM reduction, improvement of low CM-dosage examinations, and examination of patients with more severe kidney impairment. TRIAL REGISTRATION: Retrospectively registered 5 August 2022 at clinicaltrials.gov NCT05488899. KEY POINTS: • Contrast medium dosage may be halved in lower limb dual-energy CT angiography with virtual monoenergetic images at 40 keV, which may reduce contrast medium consumption in the face of a global shortage. • Experimental half-iodine-load dual-energy CT angiography at 40 keV showed higher vascular attenuation, contrast-to-noise ratio, signal-to-noise ratio, and subjective examination quality than standard iodine-load conventional. • Half-iodine dual-energy CT angiography protocols may allow us to reduce the risk of PC-AKI, examine patients with more severe kidney impairment, and provide higher quality examinations or salvage poor examinations when impaired kidney function limits the CM dose.

Nanoparticle Self-Assembly: From Design Principles to Complex Matter to Functional Materials.

The creation of matter with varying degrees of complexities and desired functions is one of the ultimate targets of self-assembly. The ability to regulate the complex interactions between the individual components is essential in achieving this target. In this direction, the initial success of controlling the pathways and final thermodynamic states of a self-assembly process is promising. Despite the progress made in the field, there has been a growing interest in pushing the limits of self-assembly processes. The main inception of this interest is that the intended self-assembled state, with varying complexities, may not be "at equilibrium (or at global minimum)", rendering free energy minimization unsuitable to form the desired product. Thus, we believe that a thorough understanding of the design principles as well as the ability to predict the outcome of a self-assembly process is essential to form a collection of the next generation of complex matter. The present review highlights the potent role of finely tuned interparticle interactions in nanomaterials to achieve the preferred self-assembled structures with the desired properties. We believe that bringing the design and prediction to nanoparticle self-assembly processes will have a similar effect as retrosynthesis had on the logic of chemical synthesis. Along with the guiding principles, the review gives a summary of the different types of products created from nanoparticle assemblies and the functional properties emerging from them. Finally, we highlight the reasonable expectations from the field and the challenges lying ahead in the creation of complex and evolvable matter.

Decision support system for sustainable groundwater management in crystalline hard rocks: implications for sugarcane agriculture, Southern India.

India is the second largest sugarcane-producing nation with water footprints ~ 104 BCM/year of which 80% met from groundwater of deep wells. The large-scale groundwater management practices were found mostly untenable affecting the sugarcane agrarian and associated sectors. We developed a cell-level (2 km × 2 km) decision support system employing the integrated hydro-geophysical investigations in sugarcane agro-watershed (399 km2) beset over granitic aquifer systems of Tattihalla River watershed, Southern India. The refined hydrogeological conceptual model derived from electrical resistivity tomography and groundwater level (head) has been accounted into the numerical modeling. The model was run on transient mode for four stress periods during 2015-2017 and validated with calculated and observed heads. The normalized RMS error 7.57% of the validated model conveys its robustness and estimates groundwater budget at the demarcated 77 cells. The theoretical scenarios for water level projections against the increased groundwater pumping rates of 10%, 25%, and 50% were generated. It showed a declining trend of water level for the projected 10-year period with varied magnitude and vulnerability for drought conditions. The different time periods of water level touching the basement (i.e., dry borewell) infers a distinct hydrogeological property of an individual cell advocating to adapt a cell level management plan. In this article, we explained two cells (nos. 12 and 60) in detail to show the varying characteristic of aquifer against the different pumping rates.

Electrostatically Directed Long-Range Self-Assembly of Nucleotides with Cationic Nanoparticles To Form Multifunctional Bioplasmonic Networks.

Precise control over interparticle interactions is essential to retain the functions of individual components in a self-assembled superstructure. Here, we report the design of a multifunctional bioplasmonic network via an electrostatically directed self-assembly process involving adenosine 5'-triphosphate (ATP). The present study unveils the ability of ATP to undergo a long-range self-assembly in the presence of cations and gold nanoparticles (AuNP). Modelling and NMR studies gave a qualitative insight into the major interactions driving the bioplasmonic network formation. ATP-Ca2+ coordination helps in regulating the electrostatic interaction, which is crucial in transforming an uncontrolled precipitation into a kinetically controlled aggregation process. Remarkably, ATP and AuNP retained their inherent properties in the multifunctional bioplasmonic network. The generality of electrostatically directed self-assembly process was extended to different nucleotide-nanoparticle systems.

Indirect CT venography of the lower extremities: impact of scan delay and patient factors on contrast enhancement and examination quality.

OBJECTIVES: Indirect computed tomography venography (CTV) is often the next imaging modality for deep vein thrombosis (DVT) when sonography is inconclusive. Our aim was to investigate the impact of scan delay and patient factors on contrast enhancement (CE) and examination quality in CTV. METHODS: Patients with clinical suspicion or clinical mimics of DVT in one large hospital were enrolled. Age, sex, body weight, height, heart rate, systolic blood pressure and cardiac output were registered. CTV of the popliteal veins was obtained at 30 s intervals at 30-210 s delays. The proportions of examinations with CE exceeding predefined cut-offs were estimated and subjective examination quality was rated. Changes in CE with time, and associations between patient factors and time to peak contrast enhancement (TPCE) were modelled with mixed effects non-linear and linear regression, respectively. RESULTS: The CE increased with increasing scan delay and reached a plateau from 120 to 210 s. The percentages of examinations achieving enhancement above cut-offs across all thresholds from 70 to 100 HU were higher at 120 s compared to 90 s (p < 0.001). After 120 s, there were no differences across scan delays for any thresholds. No patient factors showed a significant effect on TPCE. The percentage of examinations rated as acceptable was higher at 120 s compared to 90 s (p < 0.001). After 120 s, there were no statistically significant differences across scan delays. CONCLUSIONS: No patient factors were associated with TPCE in CTV. A fixed scan delay of 120-210 s yielded the best examination quality. KEY POINTS: • Contrast enhancement reached a plateau at scan delay between 90 and 120 s. • A scan delay of 120-210 s yielded the best examination quality. • No patient factors were associated with time to peak contrast enhancement.

Rapid determination and optimisation of berberine from Himalayan Berberis lycium by soxhlet apparatus using CCD-RSM and its quality control as a potential candidate for COVID-19.

SARS-CoV-2 (or COVID-19) has become a global risk and scientists are attempting to investigate antiviral vaccine. Berberis are important plants due to the presence of bioactive phytochemicals, especially berberine from the protoberberine group of benzylisoquinoline and recent studies have shown its potential in treating COVID-19. B. lycium Royle growing in subtropical regions of Asia had wide applications in Indian system of medicine. Rapid determination and novel optimisation method for berberine extraction has been developed by Soxhlet extraction utilising central composite design-response surface methodology (CCD-RSM). Berberine was detected by high-performance liquid chromatography (HPLC), and the highest yield (13.39%) was obtained by maintaining optimal extraction conditions i.e., extraction time (7.28 hrs), ethyl alcohol (52.21%) and solvent to sample ratio (21.78 v/w). Investigation of two geographic regions (Ramnagar and Srinagar) showed high berberine content in lower altitude. This novel optimisation technique has placed berberine as a potential candidate for developing pharmaceutical products for human health care.

Realization of a Novel Free-Piston Engine Generator for Hybrid-Electric Vehicle Applications.

Free-piston engine generators (FPEGs) have huge potential to be the principal energy conversion device for generating electricity from fuel as part of a hybrid-electric vehicle (EV) powertrain system. The principal advantages lay in the fact that they are theoretically more efficient, more compact, and more lightweight compared to other competing EV hybrid and range-extender solutions (internal combustion engines, rotary engines, fuel cells, etc.). However, this potential has yet to be realized. This article details a novel dual-piston FPEG configuration and presents the full layout of a system and provides technical evidence of a commercial FPEG system's likely size and weight. The work also presents the first results obtained from a project which set-out to realize an operational FPEG system in hardware through the development and testing of a flexible prototype test platform. The work presents the performance and control system characteristics, for a first of a kind system; these show great technical potential with stable and repeatable combustion events achieved with around 700 W per cylinder and 26% indicated efficiency.

Preclinical development of gastro-protective botanical candidate from Woodfordia fruticosa (Linn.) Kurz: Chemical standardization, efficacy, pharmacokinetics and safety pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Woodfordia fruticosa is traditionally used in the Ayurvedic system of medicine for the treatment of diarrhoea, poisoning, menstrual disorders, ulcers and fertility. In the present study, we report a standardized extract preparation through modern scientific approach for anti-ulcer activity. MATERIALS AND METHODS: The hydro-alcoholic extract of flowers of W. fruticosa was standardized using four chemical markers. The standardized extract was coded as ICB014. HPLC method was developed for identification and quantification of Gallic Acid, Oenothein-C, Quercetin and Kaempferol. Based on the prior published H+, K+-ATPase activity and Anti-bacterial activity against Helicobacter pylori of ICB014, was evaluated for its in-vivo efficacy in gastric ulcers models in rats followed by regulatory safety studies. RESULTS: The extract demonstrated efficacy at 31.25-62.5 mg/kg in gastric ulcer models. The extract was safe by oral route up to 2000 mg/kg in a single dose and NOAEL of 800 mg/kg in 28 days repeat study. Bioequivalent capsule formulation was prepared. CONCLUSIONS: The extract showed anti-ulcer potential and is ready for clinical evaluation.

Rhodamine scaffolds as real time chemosensors for selective detection of bisulfite in aqueous medium.

Rhodamine and its derivatives have been widely used in designing fluorescent 'turn on' cation sensors, while very few rhodamine based fluorescent probes have been reported to date for the detection of anions in water. In this article, a new rhodamine based facile and convenient 'turn on' fluorescent chemosensor 2-(2-(1-hydroxynaphthyllideneamino)ethyl)-3',6'-bis(diethylamino)spiro [isoindoline-1,9'-xanthen]-3-one (RAHN) has been developed by Schiff base condensation and characterized by standard techniques for selective detection of bisulfite anions in water. A faintly yellow colour solution of RAHN turns pink upon addition of bisulfite. Again RAHN is weakly emissive in solution but becomes strongly emissive on addition of bisulfite and the emission intensity increases gradually in the presence of increasing concentration of bisulfite. No other analytes can cause emission enhancement of RAHN, suggesting the selectivity of the probe towards bisulfite. The detection limit for bisulfite was found to be ∼0.4 µM.

Transcarotid Endovascular Thrombectomy for Acute Ischemic Stroke.

Endovascular thrombectomy (EVT) via a transfemoral approach can be extremely time-consuming or even impossible. This brief review presents 7 transcarotid EVT procedures in which reperfusion graded as 2b or 3 on the Thrombolysis In Cerebral Infarction scale was achieved. Neck hematoma in need of treatment occurred in 1 patient. Two patients died. In the remaining patients, clinical outcome was graded as a modified Rankin scale score of 3 or less. The results suggest that transcarotid access may be a realistic option for EVT when transfemoral catheterization of the internal carotid artery is not feasible.

Comparison of auditory comprehension skills in children with cochlear implant and typically developing children.

OBJECTIVE: The main goal of this study was to obtain auditory comprehension skills of native Hindi speaking children with cochlear implant and typically developing children across the age of 3-7 years and compare the scores between two groups. METHODOLOGY: A total of sixty Hindi speaking participants were selected for the study. They were divided into two groups- Group-A consisted of thirty children with normal hearing and Group-B thirty children using cochlear implants. To assess the auditory comprehension skills, Test of auditory comprehension in Hindi (TACH) was used. The participant was required to point to one of three pictures which would best correspond to the stimulus presented. Correct answers were scored as 1 and incorrect answers as 0. RESULTS: TACH was administered on for both groups. Independent t-test was applied and it was found that auditory comprehension scores of children using cochlear implant were significantly poorer than the score of children with normal hearing for all three subtests. Pearson's correlation coefficient revealed poor correlation between the scores of children with normal hearing and children using cochlear implant. CONCLUSION: The results of this study suggest that children using cochlear implant have poor auditory comprehension skills than children with normal hearing.

Application of a novel 2D cadmium(II)-MOF in the formation of a photo-switch with a substantial on-off ratio.

A novel thiocyanate bridged 2D MOF, [CdL(µ-1,3-SCN)2]n, [HL = 2-(2-(ethylamino)ethyliminomethyl)-6-ethoxyphenol] has been synthesized and characterized by X-ray crystallography. The band gap of the synthesized material in the solid state has been determined by experimental measurements and compared with the theoretical value obtained from DFT calculations. For the first time, the single crystal X-ray crystallography of a MOF has been reported along with its applicability in photosensitive devices.

Role of 3D Ultrasound and Doppler in Differentiating Clinically Suspected Cases of Leiomyoma and Adenomyosis of Uterus.

INTRODUCTION: Adenomyosis and Leiomyoma are common disorders affecting females in their reproductive age. They mimic each other in clinical presentation. Due to similarities in clinical symptoms and signs, missing one diagnosis in favour of the other is not very uncommon. Accurate diagnosis of these two conditions is important for their management. In this study we evaluated role of 3D Ultrasound and Doppler in differentiating clinically suspected cases of leiomyoma and adenomyosis of uterus. MATERIALS AND METHODS: A total of 100 patients with symptoms of abnormal uterine bleeding (with or without dysmenorrhoea), lump abdomen, chronic pelvic pain or dysparaunia who were clinically diagnosed as leiomyoma of uterus and/or adenomyosis were enrolled in to the study. These patients underwent transvaginal sonography (TVS), trans abdominal sonography (TAS) along with color and spectral Doppler sonography. Scanning was done in follicular phase of the menstrual cycle to avoid bias due high vascularity of endometrium in secretory phase. The morphology of the lesion, its vascularity, and Pulsality Index (PI), Resistive Index (RI) and Vmax (maximum velocity) were measured. Only those patients who were chosen for operative treatment were included in the study. Radiological diagnosis was then correlated with intra-operative and histopathological diagnosis. RESULTS: On imaging, while using morphological criteria and Doppler for diagnosing leiomyoma, it was found that "peripheral vascularity" was seen in 52 (89%) cases, which was the highest. Similarly while diagnosing adenomyosis it was, the criteria "central vascularity" was seen in 28 cases (93%) and "ill defined junctional zone in 3D ultrasound" was seen in 26 cases (86%), which was also observed to be highest. With the cut off values taken for PI,RI and Vmax, diagnosis of leiomyoma was found to be 93.4% sensitive, 95.6% specific and with a positive predictive value of 97.6% and negative predictive value of 88.6%. Diagnosis of adenomyosis showed a sensitivity of 95.6%, specificity of 93.4% and a positive predictive value of 88.6% and negative predictive value of 97.6%. Imaging dignosed the co-existence of both the conditions correctly in 8 (66%) cases. CONCLUSION: The parameters of blood flow impedance (that is PI, RI, and Vmax) of arteries within or around the uterine lesions revealed a consistent and significant difference between leiomyoma and adenomyosis. So apart from morphological criteria used in 3D TAS and TVS, aid of color Doppler can more accurately differentiate and diagnose these conditions.

Percutaneous closure of catheter enterotomy: feasibility determination in vivo.

AIM: To determine whether a catheter enterotomy can be percutaneously sealed with a commercially available vascular closure implant. MATERIAL AND METHODS: The study was performed using a porcine model of small intestinal obstruction. Preliminary experiments were performed to allow an informed choice between two of the most promising commercially available alternatives: A multipronged metal clip (StarClose®) and a resorbable anchored polymer plate (FemoSeal®). Thereafter closure of seven enterotomies was attempted with the most suitable implant. The deployment procedure was subjectively analyzed. The sealed enterotomies were visually evaluated and hydrostatically tested. RESULTS: StarClose was rejected for formal assessment because it was both difficult to deploy and could not ensure a watertight seal. The conventional method for deploying FemoSeal was found to be inappropriate for percutaneously closing enterotomies. However an improvised accessory allowed all seven enterotomies to be successfully sealed with the implant using a modified procedure that involved only one additional step. After closure, six of the seven enterotomies tolerated intraluminal pressure up to 65 mm Hg. CONCLUSION: FemoSeal has the potential to serve as an implant for percutaneous closure of catheter enterotomies if the deployment tool can be appropriately modified.

Cutaneous angiosarcoma of the head, neck, and face of the elderly in type 5 skin.

Cutaneous angiosarcoma is a rare, highly malignant vascular tumor with three clinical types. It is predominantly seen in the white-skinned people and rarely dealt with among the colored races. Cutaneous angiosarcoma of head and neck of the elderly is a great mimicker with many clinical presentations. The condition needs to be differentiated from several other common conditions and the diagnosis may be extremely difficult in some cases. Herein, we report the case of a 65-year-old man with type 5 skin who presented with an unusual and extensive involvement of the scalp and face presenting a diagnostic challenge.

Neurointerventional treatment in acute stroke. Whom to treat? (Endovascular treatment for acute stroke: utility of THRIVE score and HIAT score for patient selection).

PURPOSE: Intra-arterial therapy (IAT) is used increasingly as a treatment option for acute stroke caused by central large vessel occlusions. Despite high rates of recanalization, the clinical outcome is highly variable. The authors evaluated the Houston IAT (HIAT) and the totaled health risks in vascular events (THRIVE) score, two predicting scores designed to identify patients likely to benefit from IAT. METHODS: Fifty-two patients treated at the Stavanger University Hospital with IAT from May 2009 to June 2012 were included in this study. We combined the scores in an additional analysis. We also performed an additional analysis according to high age and evaluated the scores in respect of technical efficacy. RESULTS: Fifty-two patients were evaluated by the THRIVE score and 51 by the HIAT score. We found a strong correlation between the level of predicted risk and the actual clinical outcome (THRIVE p = 0.002, HIAT p = 0.003). The correlations were limited to patients successfully recanalized and to patients <80 years. By combining the scores additional 14.3 % of the patients could be identified as poor candidates for IAT. Both scores were insufficient to identify patients with a good clinical outcome. CONCLUSIONS: Both scores showed a strong correlation to poor clinical outcome in patients <80 years. The specificity of the scores could be enhanced by combining them. Both scores were insufficient to identify patients with a good clinical outcome and showed no association to clinical outcome in patients aged ≥80 years.

Focal hydrothermal ablation: preliminary investigation of a new concept.

PURPOSE: To determine whether focal tissue ablation is possible with interstitial instillation of steam. METHODS: Fresh swine livers were used. Through a 20 gauge needle, steam was instilled every 5 s, 3 (n = 5), 6 (n = 5), 9 (n = 5), or 12 (n = 5 + 5) times in a liver lobe. The ablated zones were sectioned parallel (n = 20) or perpendicular (n = 5) to the needle track. The longitudinal long and short axis diameters, or transverse long and short axis diameters of areas with discoloration on macroscopic examination, were measured. The experiment was repeated in vivo on a pig. Steam instillation was performed once every 5 s for 5 min in the liver (n = 3) and in muscle (n = 4), and temperature changes at three neighboring sites were monitored. Long and short axis diameters of the discolored areas were measured. RESULTS: A well-defined area of discoloration was invariably present at the site of steam instillation. The median longitudinal long axis diameter were 2.0, 2.5, 2.5, and 3.5 cm for 3, 6, 9, and 12 steam instillations in vitro, while median short axis diameters were 1.0, 1.5, 1.5, and 1.5 cm, respectively. Six attempts at ablation in vivo could be successfully completed. The long axis diameters of the ablated zones in the liver were 7.0 and 8.0 cm, while in muscle it ranged from 5.5 to 7.0 cm. CONCLUSION: Instillation of steam in the liver in vitro and in vivo, and in muscle in vivo rapidly leads to circumscribed zones of coagulation necrosis.

Endovascular acute stroke treatment performed by vascular interventional radiologists: is it safe and efficacious?

PURPOSE: To evaluate the safety and efficacy of neurointerventional procedures in acute stroke patients performed by a team of vascular interventional radiologists in close cooperation with diagnostic neuroradiologists and stroke neurologists and to compare the results with those of previous reports from centres with specialised interventional neuroradiologists. MATERIAL AND METHODS: A total of 39 patients with acute ischemic stroke due to large-vessel occlusion not responding to or not eligible for intravenous thrombolysis were treated with either intra-arterial thrombolysis or mechanical thrombectomy (Penumbra System or solitaire FR thrombectomy system, respectively) and included in our prospective study. Outcomes were measured using the modified Rankin scale after 90 days, and recanalization was assessed by thrombolysis using the myocardial infarction score. RESULTS: Mean patient age was 68.3 ± 14.2 years; the average National Institutes of Health Stroke Scale score at hospital admission was 17.2 (SD = 6.2 [n = 38]). Successful recanalization was achieved in 74.4 % of patients. Median time from clinical onset to recanalization was 5 h 11 min. Procedure-related complications occurred in 5 % of patients, and 7.5 % had a symptomatic intracerebral hemorrhage. Of the patients, 22.5 % died within the first 90 postprocedural days, 5 % of these from cerebral causes. Patients who were successfully recanalized had a clinical better outcome at follow-up than those in whom treatment failed. Of the patients, 35.9 % had an mRS score ≤2 after 90 days. CONCLUSION: Our results are in line with those in the published literature and show that a treatment strategy with general interventional radiologists performing neurointerventional procedures in acute stroke patients with large vessel occlusions can be achieved to the benefit of patients.