Cu-Catalyzed Direct Enantioselective Vinylogous Mannich Reaction between ß,γ-Unsaturated Pyrazoleamides and Ketimines.

A catalytic asymmetric vinylogous Mannich-type reaction between ß,γ-unsaturated amides and ketimines has been developed in excellent regio-, diastereo-, and enantioselectivities. The methodology provides an efficient approach to construct chiral homoallylic amines with a 3-amino-2-oxindole scaffold. Moreover, the transformations of the chiral products, including the removal of the pyrazole group or Boc group, the reduction of the C-C double bond, and Suzuki coupling, have been investigated.

Two-Dimensional Nonbenzenoid Heteroacene Crystals Synthesized via In-Situ Embedding of Ladder Bipyrazinylenes on Au(111).

Precisely introducing topological defects is an important strategy in nanographene crystal engineering because defects can tune π-electronic structures and control molecular assemblies. The synergistic control of the synthesis and assembly of nanographenes by embedding the topological defects to afford two-dimensional (2D) crystals on surfaces is still a great challenge. By in-situ embedding ladder bipyrazinylene (LBPy) into acene, the narrowest nanographene with zigzag edges, we have achieved the precise preparation of 2D nonbenzenoid heteroacene crystals on Au(111). Through intramolecular electrocyclization of o-diisocyanides and Au adatom-directed [2+2] cycloaddition, the nonbenzenoid heteroacene products are produced with high chemoselectivity, and lead to the molecular 2D assembly via LBPy-derived interlocking hydrogen bonds. Using bond-resolved scanning tunneling microscopy, we determined the atomic structures of the nonbenzenoid heteroacene product and diverse organometallic intermediates. The tunneling spectroscopy measurements revealed the electronic structure of the nonbenzenoid heteroacene, which is supported by density functional theory (DFT) calculations. The observed distinct organometallic intermediates during progression annealing combined with DFT calculations demonstrated that LBPy formation proceeds via electrocyclization of o-diisocyanides, trapping of heteroarynes by Au adatoms, and stepwise elimination of Au adatoms.

Prevalence of incidental colorectal cancer and polyps in autopsies of different populations: a systematic review with meta-regression analysis.

The colorectal cancer (CRC) and polyps incidentally found in autopsies represent the lesions that have not actually caused problems throughout the lifetime and thus may not need to be removed during screening. This study aimed to investigate the prevalence of incidental CRC (iCRC) and polyps in autopsies of different populations. A systematic search was performed on 19 August 2022 to identify autopsy studies that provided data on prevalence of iCRC, adenomatous polyps, hyperplastic polyps, and/or all polyps combined. The prevalence was pooled with the random-effects model. Subgroup and multivariable meta-regression analyses were conducted to investigate the heterogeneity. Forty-three eligible studies including 59,656 autopsies were identified, with 94% conducted before 1990 when CRC screening was uncommon or not available. The pooled prevalence was 0.7% (95% confidence interval [CI], 0.3-1.2%) for iCRC, 18.4% (95% CI, 13.3-24.1%) for adenomatous polyps, 16.4% (95% CI, 8.7-25.9%) for hyperplastic polyps, 26.3% (95% CI, 15.4-38.8%) for all polyps combined, and 29.9% (95% CI, 14.8-47.6%) for iCRC plus polyps. The prevalence of iCRC was higher (1.2%) in white-predominant populations but lower (0.4%) after excluding low-quality studies. Multivariable analyses showed that the prevalence of polyps was higher in white-predominant populations and higher-quality studies, increased with age, and showed a downward trend from "before 1975" through "after 1985". In conclusion, the prevalence of iCRC in autopsies was not low, considering the average lifetime risk of CRC, while incidental polyps were common. Both varied greatly in different populations. These findings may have implications when weighing the benefits and harms of screening.

Antiaromatic Sapphyrin Isomer: Transformation into Contracted Porphyrinoids with Variable Aromaticity.

Sapphyrin is a pentapyrrolic expanded porphyrin with a 22π aromatic character. Herein, we report the synthesis of a 20π antiaromatic sapphyrin isomer 1 by oxidative cyclization of a pentapyrrane precursor P5 with a terminal ß-linked pyrrole. The resulting isomer 1, containing a mis-linked bipyrrole unit in the skeleton, exhibits a reactivity for further oxidation due to the distinct antiaromatic electronic structure, affording a fused macrocycle 2, possessing a spiro-carbon-containing [5.6.5.6]-tetracyclic structure. Subsequent treatment with an acid afforded a weakly aromatic pyrrolone-appended N-confused corrole 3, and thermal fusion gave a [5.6.5.7]-tetracyclic-ring-embedded 14π aromatic triphyrin(2.1.1) analog 4. The cyclization at the mis-linked pyrrole moiety of P5 played a crucial role in synthesizing the antiaromatic porphyrinoid susceptible to facile transformation to novel porphyrinoids with variable aromaticity.

Disruption of mitochondrial complex III in cap mesenchyme but not in ureteric progenitors results in defective nephrogenesis associated with amino acid deficiency.

Oxidative metabolism in mitochondria regulates cellular differentiation and gene expression through intermediary metabolites and reactive oxygen species. Its role in kidney development and pathogenesis is not completely understood. Here we inactivated ubiquinone-binding protein QPC, a subunit of mitochondrial complex III, in two types of kidney progenitor cells to investigate the role of mitochondrial electron transport in kidney homeostasis. Inactivation of QPC in sine oculis-related homeobox 2 (SIX2)-expressing cap mesenchyme progenitors, which give rise to podocytes and all nephron segments except collecting ducts, resulted in perinatal death from severe kidney dysplasia. This was characterized by decreased proliferation of SIX2 progenitors and their failure to differentiate into kidney epithelium. QPC inactivation in cap mesenchyme progenitors induced activating transcription factor 4-mediated nutritional stress responses and was associated with a reduction in kidney tricarboxylic acid cycle metabolites and amino acid levels, which negatively impacted purine and pyrimidine synthesis. In contrast, QPC inactivation in ureteric tree epithelial cells, which give rise to the kidney collecting system, did not inhibit ureteric differentiation, and resulted in the development of functional kidneys that were smaller in size. Thus, our data demonstrate that mitochondrial oxidative metabolism is critical for the formation of cap mesenchyme-derived nephron segments but dispensable for formation of the kidney collecting system. Hence, our studies reveal compartment-specific needs for metabolic reprogramming during kidney development.

Sub-nanometer misalignment sensing for lithography with structured illumination.

Lithography for the next generation of integrated-circuit manufacturing at the 3 nm node requires sub-1-nm misalignment measurement accuracy, which is almost impossible for existing systems due to the optical diffraction limit. Herein, we propose a misalignment sensing strategy based on structured illumination. By virtue of the distinctive modulation effect of a Talbot diffractive illuminated field on moiré fringes, the measurement signals can pass unhindered through the optical system and be used for sensing. Experiments are used to demonstrate that the proposed method can implement real-time-lapse (100 Hz) misalignment sensing with an accuracy of sub-1-nm (0.31 nm @ 3σ), making it suitable for various lithography techniques (e.g., proximity, x ray, projective, and nanoimprint lithography) and fields requiring advanced precision measurement (e.g., quantum measurement, gravitational wave detection, and molecular biology).

Design of a Functional Chromene-Type Kobayashi Precursor: Gram-Scale Total Synthesis of Natural Xanthones by Highly Regioselective Aryne Annulation.

The 2,2-dimethyl-2H-chromene motif is widely found in many bioactive molecules, and is a privileged structure in the pharmaceutical arena. We have developed a concise and regioselective approach to chromenes and chromanes through an aryne-based synthetic strategy. A practical, gram-scale synthetic route to a chromene-type aryne precursor was explored. Subsequently, cyclization under mild conditions afforded tetracyclic xanthone skeletons with excellent regioselectivity. Our approach provides a concise strategy for the gram-scale synthesis of chromene-type xanthones such as 6-deoxyisojacareubin, cylindroxanthone D, staudtiixanthone D, brasilixanthone A and cudracuspixanthone O.

Concise Synthesis of Chromene/Chromane-Type Aryne Precursors and Their Applications.

The gram-scale synthesis of 5,6-, 6,7-, and 7,8-chromene/chromane-type aryne precursors and their applications in regioselective transformation to other functional derivatives is reported. Chromene/chromane-type arynes are generated under mild conditions, which can further undergo [2 + 2], [3 + 2], and [4 + 2] cycloaddition reactions, nucleophilic addition reactions, and σ-insertion reactions to produce structurally novel substituted chromenes and chromanes. The excellent regioselectivity of the reaction is facilitated by the oxygen-containing guiding groups at the ortho-position of the triple bond, which can be removed or switched to other functional groups including alkenyl, aryl, heteroaryl, and arylamino groups.

CRISPR/Cas9 engineering of albino cystinuria Type A mice.

Cystinuria Type A is a relatively common genetic kidney disease occurring in 1 in 7,000 people worldwide that results from mutation of the cystine transporter rBAT encoded by Slc3a1. We used CRISPR/Cas9 technology to engineer cystinuria Type A mice via genome editing of the C57BL/6NHsd background. These mice are an improvement on currently available models as they are on a coisogenic genetic background and have a single defined mutation. In order to use albinism to track Cas9 activity, we co-injected gRNAs targeting Slc3a1 and tyrosinase (Tyr) with Cas9 expressing plasmid DNA into mouse embryos. Two different Slc3a1 mutational alleles were derived, with homozygous mice of both demonstrating elevated urinary cystine levels, cystine crystals, and bladder stones. We used whole genome sequencing to evaluate for potential off-target editing. No off-target indels were observed for the top 10 predicted off-targets for Slc3a1 or Tyr. Therefore, we used CRISPR/Cas9 to generate coisogenic albino cystinuria Type A mice that could be used for in vivo imaging, further study, or developing new treatments of cystinuria.

Effects of long-term intradialytic oral nutrition and exercise on muscle protein homeostasis and markers of mitochondrial content in patients on hemodialysis.

Patients with end-stage kidney disease on maintenance hemodialysis commonly develop protein-energy wasting, a syndrome characterized by nutritional and metabolic abnormalities. Nutritional supplementation and exercise are recommended to prevent protein-energy wasting. In a 6-mo prospective randomized, open-label, clinical trial, we reported that the combination of resistance exercise and nutritional supplementation does not have an additive effect on lean body mass measured by dual-energy X-ray absorptiometry. To provide more mechanistic data, we performed a secondary analysis where we hypothesized that the combination of nutritional supplementation and resistance exercise would have additive effects on muscle protein accretion by stable isotope protein kinetic experiments, muscle mass by MRI, and mitochondrial content markers in muscle. We found that 6 mo of nutritional supplementation during hemodialysis increased muscle protein net balance [baseline: 2.5 (-17.8, 13.0) µg·100 mL-1·min-1 vs. 6 mo: 43.7 (13.0, 98.5) µg·100 mL-1·min-1, median (interquartile range), P = 0.04] and mid-thigh fat area [baseline: 162.3 (104.7, 226.6) cm2 vs. 6 mo: 181.9 (126.3, 279.2) cm2, median (interquartile range), P = 0.04]. Three months of nutritional supplementation also increased markers of mitochondrial content in muscle. Although the study is underpowered to detected differences, the combination of nutritional supplementation and exercise failed to show further benefit in protein accretion or muscle cross-sectional area. We conclude that long-term nutritional supplementation increases the skeletal muscle anabolic effect, the fat cross-sectional area of the thigh, and markers of mitochondrial content in skeletal muscle.

Enantioselective vinylogous aldol/lactonization cascade reaction between ß,γ-unsaturated amides and trifluoromethyl ketones: facile access to chiral trifluoromethyl dihydropyranones.

An efficient asymmetric vinylogous aldol/lactonization cascade reaction between ß,γ-unsaturated amides and trifluoromethyl ketones has been developed. Using a chiral cyclohexanediamine-based tertiary amine-thiourea catalyst, optically active trifluoromethyl dihydropyranones have been constructed in moderate-to-excellent yields (up to 99%) with excellent stereoselectivities (96-> 99.5% ee).

Quantifying the contributions of age, sex, methods, and urbanicity to the changing suicide rate trends in South Korea, 2001-2016.

PURPOSE: Suicide rates in South Korea have been one of the highest in the world. The aim of this study is to quantify the contributions of age, sex, method, and place of residence to the trends of the suicide rates between 2001 and 2016 in South Korea. METHODS: Using the suicide data obtained from the South Korean National Death Registration data set for the years 2001-2016, a Joinpoint regression analysis was conducted to determine if there was a significant change in the trend of suicide rates. Next, a decomposition analysis method was used to quantify the contributions of age, sex, method, and places of residence to the changes in the suicide rates. RESULTS: Suicide rates increased between 2001 and 2010, and decreased between 2010 and 2016. Among all the age groups, the 65-79 age group contributed most to the rise (18% in men and 7% in women) and fall (- 15% in men and - 14% in women) of suicide rates. Men contributed much more than women to the increasing trend of suicide rate (63.0% vs. 37.0%). Hanging was the key method of suicide, dominating the ups and downs of the suicide rates. The rates of suicide by pesticide poisoning have been decreasing since 2005 and suicide by charcoal burning continued to increase against a decreasing trend of suicide rate during the period of 2010-2016. The gap of the metropolitan-city-rural suicide rates was narrowing during the period under study, although the rural areas remained to have the highest suicide rates. CONCLUSION: The ups and downs of suicide rates in South Korea were not uniform across different sociodemographic groups. Age, sex, method, and place of residence contributed differently to the changes in suicide rates. Suicide prevention measures can be more focused on certain age-sex-method-region subgroups.

Enzymatic hydroxylation of L-pipecolic acid by L-proline cis-4-hydroxylases and isomers separation.

OBJECTIVES: Establish a complete and efficient method for the preparation of cis-5-hydroxy-L-pipecolic acids (cis-5HPA), including biotransformation and isomers separation and purification. RESULTS: For non-heme Fe(II)/α-KG-dependent dioxygenases, α-ketoglutarate (α-KG) has great influence on the stability of Fe(II) ions, which is also the basic of the hydroxylation reaction to the substrate. L-pipecolic acids (L-Pip) was converted to cis-5HPA by whole-cell catalysis in water, which can reduce the loss of Fe(II) ions. 120 mM L-Pip can be transformed to 93% via cell and Fe(II) ions continuous supplementation under the reaction system optimization (the molar ratio of ascorbic acid/FeSO4·7H2O and α-KG/L-Pip were 8:1 and 1:1, respectively). After the catalytic reaction, the amino protection strategy was adopted to improve the resolution of isomer products on silica gel chromatography, and the amino protected cis-5HPA was obtained with a yield of 86.7%. CONCLUSIONS: We established a method which is promising to be used for cis-5HPA largescale preparation. It also provides a suitable reference for this type of enzyme-catalyzed reaction and the hydroxy pipecolic acid isomers separation.

N-Confused Phlorin-Prodigiosin Chimera: meso-Aryl Oxidation and π-Extension Triggered by Peripheral Coordination.

An N-confused phlorin isomer bearing a dipyrrin moiety at the α-position of the confused pyrrole ring (1) was synthesized. PdII and BIII coordination at the peripheral prodigiosin-like moiety of 1 afforded the corresponding complexes 2 and 3. Reflux of 2 in triethylamine (TEA) converted the meso-phenyl into the PdII -coordinating phenoxy group to afford 4. Under the same reaction conditions, TEA was linked to the α-position of the dipyrrin unit in 3 as an N,N-diethylaminovinyl group to afford 5. Furthermore, peripheral coordination of BIII in 3 and 5 improved the planarity of the phlorin macrocycle and thus facilitated the coordination of AgIII at the inner cavity to afford 3-Ag and 5-Ag, respectively. These results provide an effective approach for developing unique porphyrinoids through peripheral coordination.

ReaxFF MD Simulations of Peptide-Grafted Gold Nanoparticles.

Functionalized gold nanoparticles have critical applications in biodetection with surface-enhanced Raman spectrum and drug delivery. In this study, reactive force field molecular dynamics simulations were performed to study gold nanoparticles, which are modified with different short-chain peptides consisting of amino acid residues of cysteine and glycine in different grafting densities in the aqueous environment. Our study showed slight facet-dependent peptide adsorption on a gold nanoparticle with the 3 nm core diameter. Peptide chains prefer to adsorb on the Au(111) facet compared to those on other facets of Au(100) and Au(110). In addition to the stable thiol interaction with gold nanoparticle surfaces, polarizable oxygen and nitrogen atoms show strong interactions with the gold surface and polarize the gold nanoparticle surfaces with an overall positive charge. Charges of gold atoms vary according to their contacts with peptide atoms and lattice positions. However, at the outmost peptide layer, the whole functionalized Au nanoparticles exhibit overall negative electrostatic potential due to the grafted peptides. Moreover, simulations show that thiol groups can be deprotonated and subsequently protons can be transferred to water molecules and carboxyl groups.

Cu(I)-Catalyzed Asymmetric Mannich Reaction of Glycine Schiff Bases to Ketimines.

A copper-catalyzed asymmetric Mannich reaction between glycine Schiff bases and ketimines has been developed. This method afforded 2-oxindole-based chiral syn-α,ß-diamino acid derivatives in high yields (89-99%) with good to excellent diastereoselectivities (≤98:2 dr) and excellent enantioselectivities (95-99% ee).

Regioselective and Enantioselective Cu(II)-Catalyzed 1,4-Conjugate Addition of Diethylzinc Reagent to Nitrodienes.

The regioselective and enantioselective Cu(II)-catalyzed 1,4-conjugate addition of diethylzinc reagent to nitrodienes is described. With 0.25 mol % of Cu(OAc)2 and chiral amidophosphine ligand L3, the 1,4-addition products were produced with a complete regioselectivity, high yields (81-98%), and excellent enantioselectivities (87-97% ee) in a short reaction time.

Construction of indazolo[3,2-a]isoquinolines via [3 + 2] cycloaddition of benzynes.

A [3 + 2] annulation protocol for the construction of N-substituted indazolo[3,2-a]isoquinolines starting from benzynes and C,N-cyclic azomethine imines was developed. A diverse range of highly functionalized products indazolo[3,2-a]isoquinolines featuring an indazole scaffold can be easily accessed via a one-step reaction under mild conditions, and they show good anti-proliferative activity on cancer cells.

Metabolic consequences of cystinuria.

BACKGROUND: Cystinuria is an inherited disorder of renal amino acid transport that causes recurrent nephrolithiasis and significant morbidity in humans. It has an incidence of 1 in 7000 worldwide making it one of the most common genetic disorders in man. We phenotypically characterized a mouse model of cystinuria type A resultant from knockout of Slc3a1. METHODS: Knockout of Slc3a1 at RNA and protein levels was evaluated using real-time quantitative PCR and immunofluorescence. Slc3a1 knockout mice were placed on normal or breeder chow diets and evaluated for cystine stone formation over time suing x-ray analysis, and the development of kidney injury by measuring injury biomarkers. Kidney injury was also evaluated via histologic analysis. Amino acid levels were measured in the blood of mice using high performance liquid chromatography. Liver glutathione levels were measured using a luminescent-based assay. RESULTS: We confirmed knockout of Slc3a1 at the RNA level, while Slc7a9 RNA representing the co-transporter was preserved. As expected, we observed bladder stone formation in Slc3a1-/- mice. Male Slc3a1-/- mice exhibited lower weights compared to Slc3a1+/+. Slc3a1-/- mice on a regular diet demonstrated elevated blood urea nitrogen (BUN) without elevation of serum creatinine. However, placing the knockout animals on a breeder chow diet, containing a higher cystine concentration, resulted in the development of elevation of both BUN and creatinine indicative of more severe chronic kidney disease. Histological examination revealed that these dietary effects resulted in worsened kidney tubular obstruction and interstitial inflammation as well as worsened bladder inflammation. Cystine is a precursor for the antioxidant molecule glutathione, so we evaluated glutathione levels in the livers of Slc3a1-/- mice. We found significantly lowered levels of both reduced and total glutathione in the knockout animals. CONCLUSIONS: Our results suggest that that diet can affect the development and progression of chronic kidney disease in an animal model of cystinuria, which may have important implications for patients with this disease. Additionally, reduced glutathione may predispose those with cystinuria to injury caused by oxidative stress. Word count: 327.

Insulin resistance is a significant determinant of sarcopenia in advanced kidney disease.

Maintenance hemodialysis (MHD) patients display significant nutritional abnormalities. Insulin is an anabolic hormone with direct effects on skeletal muscle (SM). We examined the anabolic actions of insulin, whole-body (WB), and SM protein turnover in 33 MHD patients and 17 participants without kidney disease using hyperinsulinemic-euglycemic-euaminoacidemic (dual) clamp. Gluteal muscle biopsies were obtained before and after the dual clamp. At baseline, WB protein synthesis and breakdown rates were similar in MHD patients. During dual clamp, controls had a higher increase in WB protein synthesis and a higher suppression of WB protein breakdown compared with MHD patients, resulting in statistically significantly more positive WB protein net balance [2.02 (interquartile range [IQR]: 1.79 and 2.36) vs. 1.68 (IQR: 1.46 and 1.91) mg·kg fat-free mass-1·min-1 for controls vs. for MHD patients, respectively, P < 0.001]. At baseline, SM protein synthesis and breakdown rates were higher in MHD patients versus controls, but SM net protein balance was similar between groups. During dual clamp, SM protein synthesis increased statistically significantly more in controls compared with MHD patients ( P = 0.03), whereas SM protein breakdown decreased comparably between groups. SM net protein balance was statistically significantly more positive in controls compared with MHD patients [67.3 (IQR: 46.4 and 97.1) vs. 15.4 (IQR: -83.7 and 64.7) µg·100 ml-1·min-1 for controls and MHD patients, respectively, P = 0.03]. Human SM biopsy showed a positive correlation between glucose and leucine disposal rates, phosphorylated AKT to AKT ratio, and muscle mitochondrial markers in controls but not in MHD patients. Diminished response to anabolic actions of insulin in the stimulated setting could lead to muscle wasting in MHD patients.