Molecular Co-Catalyst Confined within a Metallacage for Enhanced Photocatalytic CO2 Reduction.

The construction of structurally well-defined supramolecular hosts to accommodate catalytically active species within a cavity is a promising way to address catalyst deactivation. The resulting supramolecular catalysts can significantly improve the utilization of catalytic sites, thereby achieving a highly efficient chemical conversion. In this study, the Co-metalated phthalocyanine (Pc-Co) was successfully confined within a tetragonal prismatic metallacage, leading to the formation of a distinctive type of supramolecular photocatalyst (Pc-Co@Cage). The host-guest architecture of Pc-Co@Cage was unambiguously elucidated by single-crystal X-ray diffraction (SCXRD), NMR, and ESI-TOF-MS, revealing that the single cobalt active site can be thoroughly isolated within the space-restricted microenvironment. In addition, we found that Pc-Co@Cage can serve as a homogeneous supramolecular photocatalyst that displays high CO2 to CO conversion in aqueous media under visible light irradiation. This supramolecular photocatalyst exhibits an obvious improvement in activity (TONCO = 4175) and selectivity (SelCO = 92%) relative to the nonconfined Pc-Co catalyst (TONCO = 500, SelCO = 54%). The present strategy provided a rare example for the construction of a highly active, selective, and stable photocatalyst for CO2 reduction through a cavity-confined molecular catalyst within a discrete metallacage.

Stimuli-Responsive Topological Transformation of a Molecular Borromean Ring via Controlled Oxidation of Thioether Moieties.

A Cp*-Rh based D-shaped binuclear metallacycle and a template-free molecular Borromean ring (BR) were obtained in high yield using the semi-rigid thioether dipyridyl ligand 1,4-bis[(pyridin-4-ylthio)methyl]benzene (Bptmb). The topological transformation from a binuclear metallacycle and a BR to tetranuclear metallacycles was realized via the controlled oxidation of thioethers. The strategy used in this work can be regarded as a new form of stimuli-responsive post-synthesis modification (PSM).

Iridium-mediated regioselective B-H/C-H activation of carborane cage: a facile synthetic route to metallacycles with a carborane backbone.

One-pot reactions of carborane carboxylic acids (L), [Cp*IrCl2]2, and silver salt are reported, which lead to regioselective B-H or C-H bond activation at ambient temperature in good yields. This process is demonstrated for three carborane (o-, m-, p-) dicarboxylates, and metal-mediated B-H functionalization of a p-carborane derivative is accomplished for the first time. Two metal-induced self-assembly routes to tetra-nuclear metallacycles 3 and 5 were performed through B(4, 7)/H and B(2, 10)/H activation, respectively, and the two metallacycles were found to be stable and to exist in solution as discrete complexes. Different activation modes in the carborane cage were ascribed to the characteristic structure of the products and the electronic density differences. The analogous reaction of o-carborane monocarboxylate with the same metal precursor gave the C-H activation complex 6, indicating that the B-H bond is more stable than the C-H bond in this carborane cage. The selective activation was confirmed by DFT calculation results. In this study, a facile and efficient synthetic route has been developed through specific B-H bond activation to construct carborane-based metallacycles that are unavailable by conventional methods.

Stability analysis and synchronization in discrete-time complex networks with delayed coupling.

A new network of coupled maps is proposed in which the connections between units involve no delays but the intra-neural communication does, whereas in the work of Atay et al. [Phys. Rev. Lett. 92, 144101 (2004)], the focus is on information processing delayed by the inter-neural communication. We show that the synchronization of the network depends on not only the intrinsic dynamical features and inter-connection topology (characterized by the spectrum of the graph Laplacian) but also the delays and the coupling strength. There are two main findings: (i) the more neighbours, the easier to be synchronized; (ii) odd delays are easier to be synchronized than even ones. In addition, compared with those discussed by Atay et al. [Phys. Rev. Lett. 92, 144101 (2004)], our model has a better synchronizability for regular networks and small-world variants.

The position of the median nerve in relation to the palmaris longus tendon at the wrist: a study of 784 MR images.

Iatrogenic injury of the median nerve has been reported after endoscopic carpal tunnel release and corticoid injection. In 784 MR images of the wrist, the position of the median nerve in relation to the palmaris longus tendon was analysed. The ulnar edge of the median nerve was found medial to the palmaris longus tendon in 14% and 36% of patients at the proximal wrist crease and entrance of the carpal tunnel, respectively, compared with 23% and 40% of patients with carpal tunnel syndrome (88 patients). The position of the median nerve in relation to the palmaris longus tendon varies widely. It is suggested that the palmaris longus tendon may not be considered a safe landmark to locate the position of the median nerve and care should be taken when introducing an endoscopic instrument or during steroid injection for carpal tunnel syndrome.Level of evidence: IV.

Albumin Infusion May Improve the Prognosis of Critical COVID-19 Patients with Hypoalbuminemia in the Intensive Care Unit: A Retrospective Cohort Study.

Background: The coronavirus disease 2019 (COVID-19) pandemic has caused enormous mortality worldwide. Low albumin level is a risk factor for increasing mortality among patients in the intensive care unit (ICU). This study investigated the effect of albumin infusion on critical COVID-19 patients with hypoalbuminemia. Methods: A total of 114 COVID-19 ICU patients with hypoalbuminemia were recruited from Wuhan Leishenshan Hospital and Zhongnan Hospital of Wuhan University. Clinical features and laboratory variables were collected through electronic medical records. The cohorts were divided into two groups: albumin infusion and non-albumin infusion. Propensity-matched analysis was used to compare patients who received albumin to controls. Statistical analyses were used to investigate the survival time and inflammation-related blood biomarkers between groups. Results: Lactate dehydrogenase, interleukin (IL)-6, IL-2 receptor, and IL-8 levels were significantly downregulated in the albumin infusion group. Significant upregulations of lymphocyte counts and IL-10 were found in the albumin infusion group. There was a negative association between albumin level and D-dimer or procalcitonin levels after treatment. The albumin infusion group had a significantly longer survival time and shorter hospitalization time than control patients. Notably, a 1g increase in albumin level reduced the risk of death by approximately 7.3% after adjusting for age and sex. Patients with increased albumin levels after treatment had better prognoses than those without. Conclusion: Albumin administration can regulate COVID-19-related biomarkers and reduce the risk of death in critical patients with hypoalbuminemia. Clinicians should pay more attention to these risk factors. Targeted clinical interventions should be implemented to minimize the negative impacts of hypoalbuminemia and improve disease outcomes.

Advantages of 3-dimensional Measurements for Supraspinatus Intramuscular Fatty Evaluation in Patients With Medium to Massive Rotator Cuff Tears: Comparison With a Single Sagittal Slice.

BACKGROUND: Fatty infiltration of the rotator cuff muscles is highly related to poor outcomes after rotator cuff tears. Fat fraction (FF) based on traditional 2-dimensional measurements (2D-FF) from a single sagittal Y-view slice cannot determine intramuscular FF in the rotator cuff muscles; the newly developed 3-dimensional method (3D-FF) is supposed to precede 2D measurements for intramuscular FF evaluation in accuracy and reliability. PURPOSE: (1) To measure 3D-FF and (2) to compare 3D-FF and 2D-FF in terms of quantitative values and intra- and interobserver agreement. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Six-point Dixon magnetic resonance imaging was performed in patients with full-thickness supraspinatus tears. 2D-FF was calculated on a single sagittal Y-view. Semiautomatic segmentation software (ITK-SNAP) was used to reconstruct 3D volumes of the supraspinatus muscle and fat. 3D-FF was obtained by dividing the fat volume by the total volume of the supraspinatus muscle. A paired t test was used to compare the individual differences between 2D-FF and 3D-FF results. Linear regression and Bland-Altman analyses were performed to determine the agreement between 2D-FF and 3D-FF. Intraclass correlation coefficients (ICCs) were calculated to determine intra- and interobserver agreement. RESULTS: The 3D muscular and fatty models presented an inhomogeneous distribution of intramuscular fat in the supraspinatus, indicating the superiority of 3D-FF over 2D-FF in capturing all muscle morphologic information. 2D-FF was significantly higher than 3D-FF in the supraspinatus with large (19.5% ± 5.9% vs 16.2% ± 3.7%; P = .002) and massive (34.8% ± 13.3% vs 26.2% ± 9.4%; P < .001) rotator cuff tears. 2D-FF overestimated the FF compared with 3D-FF by >50% in 14.7% of all patients and by >15% in 67.6% of patients with large or massive RCTs. The discrepancy between 2D-FF and 3D-FF increased with increasing mean FF. The intra- and interobserver agreement of 3D-FF (ICCs, 0.89-0.99 and 0.89-0.95) was superior to that of 2D-FF (ICCs, 0.71-0.95 and 0.64-0.79). CONCLUSION: 3D-FF indicated an inhomogeneous distribution of intramuscular fat by capturing all muscle and fat morphologic information. In patients with large and massive rotator cuff tears, 2D-FF of the supraspinatus was significantly higher than 3D-FF. 3D-FF was more reliable than 2D-FF for estimating fatty infiltration in the supraspinatus, with better intra- and interobserver agreement.

Autologous Costal Cartilage Grafting for a Large Osteochondral Lesion of the Femoral Head: A 1-Year Single-Arm Study with 2 Additional Years of Follow-up.

BACKGROUND: There is currently no ideal treatment for osteochondral lesions of the femoral head (OLFH) in young patients. METHODS: We performed a 1-year single-arm study and 2 additional years of follow-up of patients with a large (defined as >3 cm 2 ) OLFH treated with insertion of autologous costal cartilage graft (ACCG) to restore femoral head congruity after lesion debridement. Twenty patients ≤40 years old who had substantial hip pain and/or dysfunction after nonoperative treatment were enrolled at a single center. The primary outcome was the change in Harris hip score (HHS) from baseline to 12 months postoperatively. Secondary outcomes included the EuroQol visual analogue scale (EQ VAS), hip joint space width, subchondral integrity on computed tomography scanning, repair tissue status evaluated with the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score, and evaluation of cartilage biochemistry by delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping. RESULTS: All 20 enrolled patients (31.02 ± 7.19 years old, 8 female and 12 male) completed the initial study and the 2 years of additional follow-up. The HHS improved from 61.89 ± 6.47 at baseline to 89.23 ± 2.62 at 12 months and 94.79 ± 2.72 at 36 months. The EQ VAS increased by 17.00 ± 8.77 at 12 months and by 21.70 ± 7.99 at 36 months (p < 0.001 for both). Complete integration of the ACCG with the bone was observed by 12 months in all 20 patients. The median MOCART score was 85 (interquartile range [IQR], 75 to 95) at 12 months and 75 (IQR, 65 to 85) at the last follow-up (range, 24 to 38 months). The ACCG demonstrated magnetic resonance properties very similar to hyaline cartilage; the median ratio between the relaxation times of the ACCG and recipient cartilage was 0.95 (IQR, 0.90 to 0.99) at 12 months and 0.97 (IQR, 0.92 to 1.00) at the last follow-up. CONCLUSIONS: ACCG is a feasible method for improving hip function and quality of life for at least 3 years in young patients who were unsatisfied with nonoperative treatment of an OLFH. Promising long-term outcomes may be possible because of the good integration between the recipient femoral head and the implanted ACCG. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Construction of tetranuclear macrocycles through C-H activation and structural transformation induced by [2+2] photocycloaddition reaction.

A series of binuclear complexes [{Cp*Ir(OOCCH(2)COO)}(2)(pyrazine)] (1b), [{Cp*Ir(OOCCH(2)COO)}(2)(bpy)] (2b; bpy=4,4'-bipyridine), [{Cp*Ir(OOCCH(2)COO)}(2)(bpe)] (3b; bpe=trans-1,2-bis(4-pyridyl)ethylene) and tetranuclear metallamacrocycles [{(Cp*Ir)(2)(OOC-C=C-COO)(pyrazine)}(2)] (1c), [{(Cp*Ir)(2)(OOC-C=C-COO)(bpy)}(2)] (2c), [{(Cp*Ir)(2)(OOC-C=C-COO)(bpe)}(2)] (3c), and [{(Cp*Ir)(2)[OOC(H(3)C(6))-N=N-(C(6)H(3))COO](pyrazine)}(2)] (1d), [{(Cp*Ir)(2)[OOC(H(3)C(6))-N=N-(C(6)H(3))COO](bpy)}(2)] (2d), [{(Cp*Ir)(2)[OOC(H(3)C(6))-N=N-(C(6)H(3))COO](bpe)}(2)] (3d) were formed by reactions of 1a-3a {[(Cp*Ir)(2)(pyrazine)Cl(2)] (1a), [(Cp*Ir)(2)(bpy)Cl(2)] (2a), and [(Cp*Ir)(2)(bpe)Cl(2)] (3a)} with malonic acid, fumaric acid, or H(2)ADB (azobenzene-4,4'-chcarboxylic acid), respectively, under mild conditions. The metallamacrocycles were directly self-assembled by activation of C-H bonds from dicarboxylic acids. Interestingly, after exposure to UV/Vis light, 3c was converted to [2+2] cycloaddition complex 4. The molecular structures of 2b, 1c, 1d, and 4 were characterized by single-crystal x-ray crystallography. Nanosized tubular channels, which may play important roles for their stability, were also observed in 1c, 1d, and 4. All complexes were well characterized by (1)H NMR and IR spectroscopy, as well as elemental analysis.

Self-assembly and guest-induced disassembly of triply interlocked [2]catenanes.

Two fascinating triply interlocked [2]catenanes and one simple triangular prism metallacage were constructed by tuning the widths of the organometallic dinuclear building blocks. Notably, the interlocked architectures were disassembled in the presence of large aromatic molecules to form their corresponding monomeric host-guest complexes.

Feasibility of Noninvasive Diagnosis of Spinal Vascular Diseases Using Time-Resolved Angiography With Stochastic Trajectories.

Background and Purpose: To determine the feasibility of time-resolved angiography with stochastic trajectories (TWIST) in the diagnosis of spinal dural arteriovenous fistula (SDAVF) and perimedullary arteriovenous fistula (PAVF). Methods: A total of 11 negative patients with TWIST examination were retrospective analyzed and then 18 patients with suspected spinal vascular diseases underwent TWIST. For negative patients, Adamkiewicz artery (AKA), great anterior radiculomedullary vein (GARV) and anterior spinal artery (ASA) were retrospective analyzed. In patients, the results of TWIST were compared with those of DSA. Results: The displaying rates of the ASA, AKA and GARV in 11 negative patients were 100, 90.9, and 90.9%, respectively. The AKA and GARV were separated on TWIST. Of 18 patients, 11 and three were diagnosed with SDAVF and PAVF, respectively. The spinal cord vascular malformation diagnosed on TWIST was consistent with DSA with an excellent intermodality agreement (Kappa = 0.92, p < 0.001). The feeding artery and side of all 11 SDAVF patients were displayed on TWIST and the results were consistent with DSA. For PAVF patients, the feeding artery in two patients and the sides as displayed on TWIST were consistent with DSA. Conclusions: TWIST enables the differentiation of the spinal artery and vein and the differential diagnosis of SDAVF and PAVF.

Selective colorimetric detection of copper (II) by a protein-based nanoprobe.

In this work, we report a novel protein-based nanoprobe (PNP) that can be employed for quantitative analysis of Cu2+ in pure water medium and real samples. Structurally, the proposed nanoprobe comprises a biofriendly protein (hen egg-white lysozyme (HEWL)) and a Cu2+-specific chromogenic agent, where HEWL acts as a nanocarrier encapsulating a structurally tailored rhodamine B derivate. The resulting PNP exhibits a hydrodynamic diameter of ~ 106 nm and efficiently disperses in water, enabling the detection of Cu2+ in pure aqueous systems without the aid of any organic co-solvents. The high sensitivity and selectivity of PNP allow the colorimetric detection of Cu2+ in the presence of other metal interferents with a low detection limit of 160 nM. The satisfying recovery of trace level Cu2+ in environmental samples demonstrate the great potential of employing PNP for the determination of Cu2+ in actual applications. Most importantly, the simple co-grinding method employing proteins and chromogenic agents provides a novel strategy to generate sensing systems that are useful detection of pollutants in aqueous samples.

Facile preparation of sulfonated biochar for highly efficient removal of toxic Pb(II) and Cd(II) from wastewater.

Biochar is deemed as the ideal material for the effective removal of heavy metals in wastewater treatment. Herein, we developed a facile one-step solvothermal method for the preparation of sulfonated biochar (SBC) from Axonopus compressus under a low-temperature condition. FTIR and XPS analysis demonstrate that plenty of -OH, -COOH and -SO3H moieties are generated on the surface of SBC during the sulfonation process. Due to high electronegativity and strong complexation of these moieties, SBC can rapidly adsorb Pb(II) and Cd(II) with capacities of 191.07 and 85.76 mg/g respectively within 5 min. SBC can be reused for 5 cycles with a negligible loss of adsorption capacity. In addition, different biomass-based biochars are prepared under the identical experimental conditions, and they are successfully applied in the treatments of Pb(II) and Cd(II). The satisfying results indicate that one-step low-temperature sulfonation could be a universal method, and various types of biomass waste could be the abundant, effective, economical material source for the treatment of environmental heavy metal pollution in future.

Stepwise formation of organometallic macrocycles, prisms and boxes from Ir, Rh and Ru-based half-sandwich units.

Over the past decade, supramolecular compounds with organometallic Ir, Rh, Ru based half-sandwich complexes have received considerable attention as materials with a variety of potential applications. The major emphasis of this tutorial review lies on the self-assembly of such organometallic half-sandwich molecular rectangles, prisms and cages with half-sandwich corners and two different rigid bifunctional ligands using an approach of stepwise construction. Synthetic methods and the structural and functional properties of the target complexes are discussed in detail.

A new supramolecular catalytic system: the self-assembly of Rh8 cage host anthracene molecules for [4 + 4] cycloaddition induced by UV irradiation.

The supramolecular assembly, used as a molecular reactor, is of great significance in host-guest chemistry. In this work, we used a tetratopic pyridyl ligand as a building block to hierarchically combine a slightly twisted cuboid with half-sandwich rhodium fragments. The cuboid directionally self-assembled hydrophobic pockets that can encapsulate conjugated molecules like anthracene (ANT) as guests in solutions, by supramolecular interactions including hydrogen bonding and hydrophobic interactions. The array of the ANT molecules in the confined pockets was subjected to a [4 + 4] photocycloaddition reaction under UV light irradiation as an external stimulus in a methanol solution. Furthermore, the mechanism underlying the process was proposed. The cuboid was fully characterized by 1H NMR, single-crystal X-ray diffraction (SCXRD), and mass spectrometry (MS), and its host-guest and cycloaddition processes were monitored by 1H NMR spectroscopy and UV-visible spectrophotometry.

A homochiral nanotubular crystalline framework of metallomacrocycles for enantioselective recognition and separation.

A highly ordered homochiral nanotubular crystalline framework was assembled from a hexameric Zn6L6metallaycle that was built from metallosalen ZnL units (H2L = (R,R)-(-)-N,N'-Bis(3-tert-butyl-5-(4- pyridyl) salicylidene)-1,2-diaminocyclohexane) by the complementary coordination of the pyridyl groups to the metal centers. Chiral channels and hydrophobic functionality presented by this structure make it an excellent host to recognize and separate racemic alcohols with high enantioselectivity (up to 99.5%). The crystalline solid can be easily recycled and reused five times without loss of crystallinity and enantioselectivity.

Electrocatalytic oxygen evolution with a cobalt complex.

The development of an earth-abundant, first-row water oxidation catalyst that operates at a high TOF and a low overpotential remains a fundamental chemical challenge. Cobalt complexes are important members of water oxidation catalysts. Herein, we report a cobalt-based robust homogeneous water oxidation catalyst, which can electrocatalyze water oxidation at a high pH and a low overpotential (η = 520 mV) in phosphate buffer. This homogeneous system exhibits a high turnover frequency (about 5 s-1) of catalyzing water oxidation to produce oxygen at η = 720 mV. We speculate the mechanism of the reaction that O-O bond formation prefers a HO-OH coupling in catalytic water oxidation.

Anion-directed self-assembly of two half-sandwich ruthenium-based metallamacrocycles as catalysts for water oxidation.

The binuclear [η(6) -(cymene)Ru(L)]2 (OTf)2 (TfO(-) =trifluoromethanesulfonate) and tetranuclear [η(6) -(cymene)Ru(L)]4 (NO3 )4 metallacycles were prepared by treating the pyridyl-substituted 8-hydroxyquinoline ligand (E)-2-[2-(pyridin-3-yl)vinyl]quinolin-8-ol (HL) with [(p-cymene)Ru(µ-Cl)Cl]2 in the presence of AgOTf or AgNO3 . The molecular structures of these complexes were confirmed by single-crystal X-ray diffraction, which revealed that both complexes have macrocycle frameworks induced by the TfO(-) and NO3 (-) counteranions, respectively. The electrochemical properties of the two metallacycles were investigated by cyclic voltammetry, which showed that they have great potential as catalysts for water oxidation. Good efficiency was obtained by utilizing the nitrate complex as a water oxidation catalyst in the presence of a Ce(IV) salt as an oxidant at high pH values.

A new copper species based on an azo-compound utilized as a homogeneous catalyst for water oxidation.

A new azo-complex [(L)Cu(II)(NO3)] [L = (E)-3-(pyridin-2-yldiazenyl)naphthalen-2-ol (HL)], was prepared via a one-pot synthetic method at 60 °C and was structurally characterized by IR, EA, PXRD and single crystal X-ray diffraction. In addition, TGA studies indicated that the complex was stable in air. The redox properties were determined by cyclic voltammetry, which revealed that the complex could be utilized as a catalyst for water oxidation under mild conditions. Subsequently, the complex was employed as a catalyst to take part in water oxidation reaction in the presence of a Ce(IV) salt utilized as an oxidant at pH 11 in PBS (Phosphate Buffered Saline) solution. The results suggested that the catalyst exhibited a high stability and activity toward water oxidation reaction under these conditions with an initial TOF of 4.0 kPa h(-1). Calculation methodology was performed to study the mechanism of the reaction, which revealed that in this catalytic process, the initial oxidation of Cu(II) to Cu(III) occurred by the formation of an intermediate "Cu(III)-O-O-Cu(III)". The formation of this intermediate, resulted in a release of oxygen and closing of the catalytic cycle.