Direct Band Gap Semiconductors with Two- and Three-Dimensional Triel-Phosphide Frameworks (Triel=Al, Ga, In).

Recently, several ternary phosphidotrielates and -tetrelates have been investigated with respect to their very good ionic conductivity, while less focus was pointed towards their electronic structures. Here, we report on a novel series of compounds, in which several members possess direct band gaps. We investigated the known compounds Li3AlP2, Li3GaP2, Li3InP2, and Na3InP2 and describe the synthesis and the crystal structure of novel Na3In2P3. For all mentioned phosphidotrielates reflectance UV-Vis measurements reveal direct band gaps in the visible light region with decreasing band gaps in the series: Li3AlP2 (2.45 eV), Li3GaP2 (2.18 eV), Li3InP2 (1.99 eV), Na3InP2 (1.37 eV), and Na3In2P3 (1.27 eV). All direct band gaps are confirmed by quantum chemical calculations. The unexpected property occurs despite different structure types. As a common feature all compounds contain EP4 tetrahedra, which share exclusively vertices for E=In and vertices as well as edges for E=Al and Ga. The structure of the novel Na3In2P3 is built up by a polyanionic framework of six-membered rings of corner-sharing InP4 tetrahedra. As a result, the newly designed semiconductors with direct band gaps are suitable for optoelectronic applications, and they can provide significant guidance for the design of new functional semiconductors.

Photochargeable Mn-Based Metal-Organic Framework and Decoupled Photocatalysis.

Designing multifunctional materials that mimic the light-dark decoupling of natural photosynthesis is a key challenge in the field of energy conversion. Herein, we introduce MnBr-253, a precious metal-free metal-organic framework (MOF) built on Al nodes, bipyridine linkers and MnBr(CO)3(bipyridine) complexes. Upon irradiation, MnBr-253 colloids demonstrate an electron photocharging capacity of ~42 C ⋅ g-1 MOF, with state-of-the-art photocharging rate (1.28 C ⋅ s-1 ⋅ g-1 MOF) and incident photon-to-electron conversion efficiency of ~9.4 % at 450 nm. Spectroscopic and computational studies support effective electron accumulation at the Mn complex while high porosity and Mn loading account for the notable electron storage performance. The charged MnBr-253 powders were successfully applied for hydrogen evolution under dark conditions thus emulating the light-decoupled reactivity of photosynthesis.

Vectorial Catalysis in Surface-Anchored Nanometer-Sized Metal-Organic Frameworks-Based Microfluidic Devices.

Vectorial catalysis-controlling multi-step reactions in a programmed sequence and by defined spatial localization in a microscale device-is an enticing goal in bio-inspired catalysis research. However, translating concepts from natural cascade biocatalysis into artificial hierarchical chemical systems remains a challenge. Herein, we demonstrate integration of two different surface-anchored nanometer-sized metal-organic frameworks (MOFs) in a microfluidic device for modelling vectorial catalysis. Catalyst immobilization at defined sections along the microchannel and a two-step cascade reaction was conducted with full conversion after 30 seconds and high turnover frequencies (TOF≈105  h-1 ).

Understanding entrapped molecular photosystem and metal-organic framework synergy for improved solar fuel production.

Artificial photosystems assembled from molecular complexes, such as the photocatalyst fac-ReBr(CO)3(4,4'-dcbpy) (dcbpy = dicarboxy-2,2'-bipyridine) and the photosensitiser Ru(bpy)2(5,5'-dcbpy)Cl2 (bpy = 2,2'-bipyridine), are a wide-spread approach for solar fuel production. Recently metal-organic framework (MOF) entrapping of such complexes was demonstrated as a promising concept for catalyst stabilisation and reaction environment optimisation in colloidal-based CO2 reduction. Building on this strategy, here we examined the influence of MIL-101-NH2(Al) MOF particle size, the electron donor source, and the presence of an organic base on the photocatalytic CO2-to-CO reduction performance, and the differences to homogeneous systems. A linear relation between smaller scaffold particle size and higher photocatalytic activity, longer system lifetimes for benign electron donors, and increased turnover numbers (TONs) with certain additive organic bases, were determined. This enabled understanding of key molecular catalysis phenomena and synergies in the nanoreactor-like host-guest assembly, and yielded TONs of ∼4300 over 96 h of photocatalysis under optimised conditions, surpassing homogeneous TON values and lifetimes.

Host-Guest Interactions in a Metal-Organic Framework Isoreticular Series for Molecular Photocatalytic CO2 Reduction.

A strategy to improve homogeneous molecular catalyst stability, efficiency, and selectivity is the immobilization on supporting surfaces or within host matrices. Herein, we examine the co-immobilization of a CO2 reduction catalyst [ReBr(CO)3 (4,4'-dcbpy)] and a photosensitizer [Ru(bpy)2 (5,5'-dcbpy)]Cl2 using the isoreticular series of metal-organic frameworks (MOFs) UiO-66, -67, and -68. Specific host pore size choice enables distinct catalyst and photosensitizer spatial location-either at the outer MOF particle surface or inside the MOF cavities-affecting catalyst stability, electronic communication between reaction center and photosensitizer, and consequently the apparent catalytic rates. These results allow for a rational understanding of an optimized supramolecular layout of catalyst, photosensitizer, and host matrix.

A Randomized Prospective Placebo-Controlled Study of the Effects of Lavender Aromatherapy on Preoperative Anxiety in Cataract Surgery Patients.

PURPOSE: To determine if lavender aromatherapy can reduce preoperative anxiety in cataract surgery patients. DESIGN: Single-center prospective randomized placebo-controlled trial. METHODS: Seventy-five patients awaiting cataract surgery were randomized to lavender essential oil or grape seed oil (control) and administered the State-Trait Anxiety Inventory. Vital signs were also recorded. FINDINGS: Patients in the lavender group showed greater improvements in self-reported anxiety using the State-Trait Anxiety Inventory (P = .023, two-sample t test). Compared with the control group, the effects of lavender on the reduction of anxiety were statistically significant when adjusting for age, gender, and baseline scores (P = .012, analysis of covariance). CONCLUSIONS: Lavender aromatherapy reduced anxiety in preoperative cataract surgery patients.

Percutaneous liver biopsy: pathologic diagnosis and complications in children.

OBJECTIVE: The aim of this study was to determine patient factors that predict diagnostic failure or increased risk of bleeding complications following percutaneous liver biopsy in children. METHODS: A retrospective review of all children undergoing percutaneous liver biopsy at a single institution between July 2008 and July 2011 was performed. Demographics, comorbid conditions, preprocedural diagnoses/indications, procedural details, laboratory data, pathologic diagnosis, and complications were recorded. Continuous data were analyzed by Wilcoxon test and categorical data by Fisher exact test to determine statistical significance. RESULTS: Two hundred thirteen children (104 girls) with a median age of 7 years (range 1 week-22 years) underwent 328 percutaneous liver biopsies. Nine (4.2%) experienced a decrease in hemoglobin >2 g/dL, 7 required transfusion (3.3%), and 1 patient died (0.5%). Younger age (1.8 vs 84 months, P = 0.05) and lower preprocedural hematocrit (29.3 vs 34.3, P = 0.05) predicted bleeding complications, whereas the number of biopsies, comorbid conditions, and coagulopathy did not. Sixty-three (19.2%) biopsies were insufficient for definitive histologic evaluation on initial biopsy in 57 patients. Twenty-one of 57 patients (37%) underwent repeat percutaneous biopsy and 3 of 57 (8%) underwent surgical biopsy. Biopsy provided definitive diagnosis in 86% of cases when repeat biopsy was performed. Shorter specimen length (1.4 vs 1.7 cm, P < 0.01) and biopsies performed for unexplained elevation of liver function tests (34.9% vs 16.7%, P < 0.01) were predictive of nondiagnosis. CONCLUSIONS: Percutaneous liver biopsy is safe with a low rate of bleeding-related complications. Ensuring adequate sample length and careful patient selection may further increase the diagnostic yield.

Decoupled Solar Energy Storage and Dark Photocatalysis in a 3D Metal-Organic Framework.

Materials enabling solar energy conversion and long-term storage for readily available electrical and chemical energy are key for off-grid energy distribution. Herein, the specific confinement of a rhenium coordination complex in a metal-organic framework (MOF) unlocks a unique electron accumulating property under visible-light irradiation. About 15 C gMOF -1 of electric charges can be concentrated and stored for over four weeks without loss. Decoupled, on-demand discharge for electrochemical reactions and H2 evolution catalysis is shown and light-driven recharging can be conducted for >10 cycles with ≈90% of the initial charging capacity retained. Experimental investigations and theoretical calculations link electron trapping to MOF-induced geometry constraints as well as the coordination environment of the Re-center, highlighting the key role of MOF confinement on molecular guests. This study serves as the seminal report on 3D porous colloids achieving photoaccumulation of long-lived electrons, unlocking dark photocatalysis, and a path toward solar capacitor and solar battery systems.

Photocatalytic CO2 -to-Syngas Evolution with Molecular Catalyst Metal-Organic Framework Nanozymes.

Syngas, a mixture of CO and H2 , is a high-priority intermediate for producing several commodity chemicals, e.g., ammonia, methanol, and synthetic hydrocarbon fuels. Accordingly, parallel sunlight-driven catalytic conversion of CO2 and protons to syngas is a key step toward a sustainable energy cycle. State-of-the-art catalytic systems and materials often fall short as application-oriented concurrent CO and H2 evolution requires challenging reaction conditions which can hamper stability, selectivity, and efficiency. Here a light-harvesting metal-organic framework hosting two molecular catalysts is engineered to yield colloidal, water-stable, versatile nanoreactors for photocatalytic syngas generation with highly controllable product ratios. In-depth fluorescence, X-ray, and microscopic studies paired with kinetic analysis show that the host delivers energy efficiently to active sites, conceptually yielding nanozymes. This unlocked sustained CO2 reduction and H2 evolution with benchmark turnover numbers and record incident photon conversions up to 36%, showcasing a highly active and durable all-in-one material toward application in solar energy-driven syngas generation.

Flap-off epi-LASIK versus automated epithelial brush in PRK: a prospective comparison study of pain and reepithelialization times.

PURPOSE: To compare the effect of flap-off epi-LASIK versus automated brush epithelial removal on pain and wound healing in low myopic photorefractive keratectomy (PRK). METHODS: In this prospective intraindividual study 60 patients received surface ablation in each eye. Epithelial removal was performed by an automated brush technique in one eye (brush group) and epi-LASIK with flap removal (flap-off group) in the fellow eye. The epithelial defect size was measured daily after surgery until both eyes were reepithelialized. Postoperative pain on a scale from 0 to 6 and topical and oral analgesic medication use was recorded until the bandage contact lens was removed. RESULTS: The flap-off group had significantly less postoperative pain on days 1 (P=.0003), 2 (P=.0001), 3 (P<.0001), and 4 (P<.0001) compared to the brush group. However, the average difference in pain scores between groups was only 0.33 points out of 6. No difference was noted in the normalized overall percentage rate of healing over the first 4 days in the flap-off group (5.41±1.39%/hour) compared to the brush group (5.42±1.94%/hour) (P=.97). CONCLUSIONS: The flap-off group showed a statistically but not clinically significant advantage over the brush group in pain scores. However, no difference was noted in the percentage rate of epithelial healing time between the two groups.

Phase II study of pre-irradiation chemotherapy for childhood intracranial ependymoma. Children's Cancer Group protocol 9942: a report from the Children's Oncology Group.

PURPOSE: Standard therapy for childhood intracranial ependymoma is maximal tumor resection followed by involved-field irradiation. Although not used routinely, chemotherapy has produced objective responses in ependymoma, both at recurrence and in infants. Because the presence of residual tumor following surgery is consistently associated with inferior outcome, the potential impact of pre-irradiation chemotherapy was investigated. METHODS: Between 1995 and 1999, the Children's Cancer Group undertook a Phase II trial of pre-irradiation chemotherapy in children 3-21 years of age with intracranial ependymoma and radiological evidence of post-operative residual tumor. RESULTS: Of 84 patients, 41 had residual tumor, and were given four cycles of cisplatin-based chemotherapy prior to irradiation. Of 35 patients fully evaluable for response to chemotherapy, 14 (40%) demonstrated complete response, 6 (17%) partial response, 10 (29%) minor response or stable disease, and 5 (14%) demonstrated progressive tumor growth. For the entire group, 5-year overall survival (OS) and event-free survival (EFS) was 71 ± 6%, and 57 ± 6%, respectively. The pre-irradiation chemotherapy group demonstrated EFS comparable to that of patients with no residual tumor who received irradiation alone (55 ± 8% vs. 58 ± 9%, P = 0.45). Any benefit of chemotherapy was restricted to patients with greater than 90% tumor resection. CONCLUSIONS: Children with near total resection of ependymoma may benefit from pre-irradiation chemotherapy. Patients with subtotal resection have inferior outcome despite responses to chemotherapy, and should be considered for second-look surgery prior to irradiation. Pediatr Blood Cancer 2012; 59: 1183-1189. © 2012 Wiley Periodicals, Inc.

Colonic venous malformation and portal hypertension: association, management, and review of the literature.

We present a case of an adolescent with lower gastrointestinal bleeding caused by a colorectal venous malformation (VM) with concomitant portal hypertension. After an episode of massive gastrointestinal bleeding, we performed an extended right hemicolectomy and resection of the VM and selective portosystemic shunt. Here, we present the case and review the literature regarding portal hypertension and gastrointestinal vascular malformations. Additionally, we discuss the physiologic and hemodynamic effects of gastrointestinal vascular malformations on the portal system.

Analysis of covariance: A useful tool for the pharmacologist to reduce variation and improve precision using fewer animals.

Commonly employed methods for reducing unwanted variation in pharmacology studies, such as data normalisation to baseline or control values, are suboptimal and potentially detrimental. This article highlights the value of using a technique called analysis of covariance (ANCOVA) to incorporate supplementary measurements in the analysis to improve the precision of the treatment comparisons and reduce the required sample size. This technique is not new, but unfortunately, it has been under-utilised in the statistical analysis of pharmacological data. ANCOVA is an extension of the methods of analysis of variance (ANOVA) and simply requires that we take additional measurements that are statistically related to the response measurements but which are themselves unaffected by the treatments being studied. Most often, in pharmacological studies, these additional measurements would be the baseline or pre-dose reading corresponding to the response measurement. As many pharmacologists routinely make use of baseline readings in their analysis through normalisation, this article describes a more appropriate method to account for the variation in the baseline readings.

Topology- and wavelength-governed CO2 reduction photocatalysis in molecular catalyst-metal-organic framework assemblies.

Optimising catalyst materials for visible light-driven fuel production requires understanding complex and intertwined processes including light absorption and catalyst stability, as well as mass, charge, and energy transport. These phenomena can be uniquely combined (and ideally controlled) in porous host-guest systems. Towards this goal we designed model systems consisting of molecular complexes as catalysts and porphyrin metal-organic frameworks (MOFs) as light-harvesting and hosting porous matrices. Two MOF-rhenium molecule hybrids with identical building units but differing topologies (PCN-222 and PCN-224) were prepared including photosensitiser-catalyst dyad-like systems integrated via self-assembled molecular recognition. This allowed us to investigate the impact of MOF topology on solar fuel production, with PCN-222 assemblies yielding a 9-fold turnover number enhancement for solar CO2-to-CO reduction over PCN-224 hybrids as well as a 10-fold increase compared to the homogeneous catalyst-porphyrin dyad. Catalytic, spectroscopic and computational investigations identified larger pores and efficient exciton hopping as performance boosters, and further unveiled a MOF-specific, wavelength-dependent catalytic behaviour. Accordingly, CO2 reduction product selectivity is governed by selective activation of two independent, circumscribed or delocalised, energy/electron transfer channels from the porphyrin excited state to either formate-producing MOF nodes or the CO-producing molecular catalysts.

Riboflavin and ultraviolet light a therapy as an adjuvant treatment for medically refractive Acanthamoeba keratitis: report of 3 cases.

PURPOSE: To present the first 3 cases of Acanthamoeba keratitis (AK), unresponsive to medical treatment, that were successfully treated with a novel adjunctive therapy using ultraviolet light A (UVA) and riboflavin (B2). DESIGN: Interventional case series. PARTICIPANTS: Two patients with confirmed AK and 1 patient with presumptive AK, which were all refractive to multidrug conventional therapy. INTERVENTION: Two treatment sessions involving topical application of 0.1% B2 solution to the ocular surface combined with 30 minutes of UVA irradiation focused on the corneal ulcer. MAIN OUTCOME MEASURES: Clinical examination by slit lamp, confocal microscopy, and histopathology, when available. RESULTS: All patients in these series showed a rapid reduction in their symptoms and decreased ulcer size after the first treatment session. The progress of the clinical improvement began to slow after 1 to 3 weeks of the first application and was then renewed after the second application. All ancillary signs of inflammation mostly resolved after the second treatment session. The ulcers in all patients continued to decrease and were closed within 3 to 7 weeks of the first application. Two patients developed dense central corneal scars, and penetrating keratoplasty was performed for visual rehabilitation. Histopathologic examination of the excised tissue revealed no Acanthamoeba organisms. The remaining patient had no symptoms or signs of infection, both clinically and by confocal microscopy, and was left with a semitransparent eccentric scar that did not affect visual acuity. CONCLUSIONS: The adjunctive use of UVA and B2 therapy seems to be a possible alternative for selected cases of medication-resistant AK.

Recalcitrant Pseudomonas Aeruginosa Keratitis with Hyphaema.

PURPOSE: To report a case of recalcitrant pseudomonas keratitis with a rare presentation of hyphaema. OBSERVATION: A 45-year-old female was noted to have contact lens-related pseudomonas keratitis with hyphaema. The organism was refractory to multiple antibiotics and only responded to Tazocin eye drops. CONCLUSION AND IMPORTANCE: Hyphaema is a rare presentation in bacterial keratitis and could represent infection with an especially virulent organism. Use of Aspirin could precipitate hyphaema in infective keratitis. Alternative antibiotic choices such as Tazocin, colistin, meropenem, and imipenem can be considered when standard therapy is ineffective for multidrug-resistant Pseudomonas keratitis.

Retained anterior chamber graphite foreign body with delayed inflammation.

PURPOSE: To report a case of retained anterior chamber graphite foreign body with subsequent inflammation 20 years later. OBSERVATIONS: A 29-year-old female who presented with first episode of acute blurring of vision and eye redness was noted to have a retained intraocular graphite foreign body in her anterior chamber. She recalled being accidently hit by a mechanical pencil 20 years ago. CONCLUSIONS AND IMPORTANCE: Retained intraocular graphite foreign bodies are inert and generally do not cause inflammation. This is the longest reported duration of retained anterior chamber graphite foreign body that developed subsequent inflammation and corneal endothelial damage only 20 years later.

Variation in radiation dosing among pediatric trauma patients undergoing head computed tomography scan.

BACKGROUND: When head injured children undergo head computed tomography (CT), radiation dosing can vary considerably between institutions, potentially exposing children to excess radiation, increasing risk for malignancies later in life. We compared radiation delivery from head CTs at a level 1 pediatric trauma center (PTC) versus scans performed at referring adult general hospitals (AGHs). We hypothesized that children at our PTC receive a significantly lower radiation dose than children who underwent CT at AGHs for similar injury profiles. METHODS: We retrospectively reviewed the charts of all patients younger than 18 years who underwent CT for head injury at our PTC or at an AGH before transfer between January 1 and December 31, 2019. We analyzed demographic and clinical data. Our primary outcome was head CT radiation dose, as calculated by volumetric CT dose index (CTDIvol) and dose-length product (DLP; the product of CTDIvol and scan length). We used unadjusted bivariate and multivariable linear regression (adjusting for age, weight, sex) to compare doses between Children's Hospital Los Angeles and AGHs. RESULTS: Of 429 scans reviewed, 193 were performed at our PTC, while 236 were performed at AGHs. Mean radiation dose administered was significantly lower at our PTC compared with AGHs (CTDIvol 20.3/DLP 408.7 vs. CTDIvol 30.6/DLP 533, p < 0.0001). This was true whether the AGH was a trauma center or not. After adjusting for covariates, findings were similar for both CTDIvol and DLP. Patients who underwent initial CT at an AGH and then underwent a second CT at our PTC received less radiation for the second CT (CTDIvol 25.6 vs. 36.5, p < 0.0001). CONCLUSIONS: Head-injured children consistently receive a lower radiation dose when undergoing initial head CT at a PTC compared with AGHs. This provides a basis for programs aimed at establishing protocols to deliver only as much radiation as necessary to children undergoing head CT. LEVEL OF EVIDENCE: Care Management/Therapeutic, level IV.