Kidney disease in trials of perioperative tranexamic acid

STUDY OBJECTIVE

To assess how kidney disease is handled in randomized trials evaluating the safety and efficacy of perioperative tranexamic acid, and to evaluate its effects across levels of kidney function.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

SETTING

We screened studies from a previous comprehensive systematic review, and updated its search of PubMed, Embase, and Cochrane CENTRAL to July 31, 2023.

PATIENTS

Patients undergoing non-obstetric surgery.

INTERVENTIONS

Intravenous tranexamic acid compared to placebo or usual care without tranexamic acid.

MEASUREMENT

We summarized the handling of kidney disease in eligibility criteria, dose adjustments for kidney function, and effects of tranexamic acid on thrombotic events, seizures, and bleeding by subgroups of kidney function.

MAIN RESULTS

We evaluated 300 trials with 53,085 participants; 45,958 participants (86.6%) were enrolled in 228 trials (76.0%) that explicitly excluded patients with kidney disease. Definitions of kidney diseased used for exclusion varied widely. Most were non-specific and some corresponded to mild disease. Only 5 trials adjusted dosing for kidney function. Meta-analysis of two large trials found tranexamic acid unlikely to substantially increase or decrease the occurrence of thrombotic events in patients with eGFR <60 mL/min/1.73m2 (RR, 0.95; 95% CI: 0.83 to 1.07) or ≥ 60 mL/min/1.73m2 (RR, 1.00; 95% CI, 0.91 to 1.11; P for subgroup difference = 0.47), but both trials excluded patients with severe kidney disease. No analysis could be performed regarding seizure risk. One large trial in noncardiac surgery reported similar reduction in bleeding across subgroups of kidney function but excluded patients with creatinine clearance <30 mL/min.

CONCLUSIONS

The large evidence base supporting perioperative tranexamic acid suffers from broad and unjustified exclusion of patients with kidney disease. Typical perioperative dosing of tranexamic acid is likely safe and effective in patients with creatinine clearance >30 mL/min, but effects in more severe kidney disease are unknown.

MCT1-mediated transport of valeric acid promotes porcine preimplantation embryo development by improving mitochondrial function and inhibiting the autophagic AMPK-ULK1 pathway

Oocytes and embryos are highly sensitive to environmental stress in vivo and in vitro. During in vitro culture, many stressful conditions can affect embryo quality and viability, leading to adverse clinical outcomes such as abortion and congenital abnormalities. In this study, we found that valeric acid (VA) increased the mitochondrial membrane potential and ATP content, decreased the level of reactive oxygen species that the mitochondria generate, and thus improved mitochondrial function during early embryonic development in pigs. VA decreased expression of the autophagy-related factors LC3B and BECLIN1. Interestingly, VA inhibited expression of autophagy-associated phosphorylation-adenosine monophosphate-activated protein kinase (p-AMPK), phosphorylation-UNC-51-like autophagy-activated kinase 1 (p-ULK1, Ser555), and ATG13, which reduced apoptosis. Short-chain fatty acids (SCFAs) can signal through G-protein-coupled receptors on the cell membrane or enter the cell directly through transporters. We further show that the monocarboxylate transporter 1 (MCT1) was necessary for the effects of VA on embryo quality, which provides a new molecular perspective of the pathway by which SCFAs affect embryos. Importantly, VA significantly inhibited the AMPK-ULK1 autophagic signaling pathway through MCT1, decreased apoptosis, increased expression of embryonic pluripotency genes, and improved embryo quality.

Sex identification of birds in Taipei Zoo

As a conservation and breeding institution for birds, Taipei Zoo plays an important role in restoring endangered species. As approximately half of all bird species are monomorphic, precisely confirming the sex of individuals is critical for the management of ex-situ conservation breeding populations, as well as for understanding the sex ratio of those in the wild. Generally, PCR is used more reliably for sex determination versus traditional methods such as plumage, behavior or hormone levels. Nevertheless, the various primer sets and annealing temperatures vary between species, and so inaccurate sexing can occasionally happen due to inadequate PCR conditions. To reduce the probability of misidentification, and to establish a PCR condition database for sex determination across the diverse range of avian taxa, we tested multiple primer sets and annealing temperatures for amplification of the bird sex-specific gene fragments (CHD1) for each captive or rescued avian species held at Taipei Zoo since 2014. A total of 162 species across 22 orders were tested using one or two primer sets. One hundred and fifty-five species were successfully sexed by the primer set 2550F/2718R and the success rate of sex typing reached over 90% of species tested in each order. Most species have suitable PCR annealing temperatures between 45°C and 55°C, and the species in the same avian taxa showed similar results in temperature. This indicates that it is possible to select the annealing temperature of other species in the same family when the species had not been tested before. We expect this study will improve the success rate of identifying sex by using applicable PCR conditions and reduce the time for searching references every time before attempts to PCR sex birds.

An alleviative effect of Lonicerae japonicae flos water extract against liver fibrogenesis in vitro and in vivo

Lonicerae japonicae (L. japonicae) flos is a medical and food homology herb. This study investigated the phenolic acid and flavonoid contents in L. japonicae flos water extract solution (LJWES) and the preventive effects of LJWES against liver fibrogenesis via FL83B cells and rats. LJWES contains many polyphenols, such as chlorogenic acid, morin, and epicatechin. LJWES increased cell viability and decreased cytotoxicity in thioacetamide (TAA)-treated FL83B cells (75 mM) (p < .05). LJWES decreased (p < .05) gene expressions of Tnf-α, Tnfr1, Bax, and cytochrome c but upregulated Bcl-2 and Bcl-xl in TAA-treated cells; meanwhile, increased protein levels of P53, cleaved caspase 3, and cleaved caspase 9 in TAA treated cells were downregulated (p < .05) by LJWES supplementation. In vivo, results indicated that TAA treatment increased serum liver damage indices (alanine aminotransferase [ALT] and alkaline phosphatase [ALP]) and cytokines (interleukin-6 and transforming growth factor-β1) levels and impaired liver antioxidant capacities (increased thiobarbituric acid reactive substance value but decreased catalase/glutathione peroxidase activities) in rats (p < .05) while LJWES supplementation amended (p < .05) them. Liver fibrosis scores, collagen deposition, and alpha-smooth muscle actin deposition in TAA-treated rats were also decreased by LJWES supplementation (p < .05). To sum up, LJWES could be a potential hepatoprotective agent against liver fibrogenesis by enhancing antioxidant ability, downregulating inflammation in livers, and reducing apoptosis in hepatocytes.

Hydride-doped coinage metal superatoms and their catalytic applications

Superatomic constructs have been identified as a critical component of future technologies. The isolation of coinage metal superatoms relies on partially reducing metallic frameworks to accommodate the mixed valent state required to generate a superatom. Controlling this reduction requires careful consideration in reducing the agent, temperature, and the ligand that directs the self-assembly process. Hydride-based reducing agents dominate the synthetic wet chemical routes to coinage metal clusters. However, within this category, a unique subset of superatoms that retain a hydride/s within the nanocluster post-reduction have emerged. These stable constructs have only recently been characterized in the solid state and have highly unique structural features and properties. The difficulty in identifying the position of hydrides in electron-rich metallic constructs requires the combination and correlation of several analytical methods, including ESI-MS, NMR, SCXRD, and DFT. This text highlights the importance of NMR in detecting hydride environments in these superatomic systems. Added to the complexity of these systems is the dual nature of the hydride, which can act as metallic hydrogen in some cases, resulting in entirely different physical properties. This review includes all hydride-doped superatomic nanoclusters emphasizing synthesis, structure, and catalytic potential.

Doping effect on a two-electron silver nanocluster

This study investigates the effects of metal addition and doping of a 2-electron silver superatom, [Ag10{S2P(OiPr)2}8] (Ag10). When Ag+ is added to Ag10 in THF solution, [Ag11{S2P(OiPr)2}8(OTf)] (Ag11) is rapidly formed almost quantitatively. When the same method is used with Cu+, a mixture of alloys, [CuxAg11-x{S2P(OiPr)2}8]+ (x = 1-3, CuxAg11-x), is obtained. In contrast, introducing Au+ to Ag10 leads to decomposition. The structural and compositional analysis of Ag11 was characterized by single-crystal X-ray diffraction (SCXRD), ESI-MS, NMR spectroscopy, and DFT calculations. While no crystal structure was obtained for CuxAg11-x, DFT calculations provide insights into potential sites for copper location. The absorption spectrum exhibits a notable blue shift in the low-energy band after copper doping, contrasting with that of the slight shift observed in 8-electron Cu-doped Ag nanoclusters. Ag11 and CuxAg11-x are strongly emissive at room temperature, and solvatochromism across different organic solvents is highlighted. This study underscores the profound influence of metal addition and doping on the structural and optical properties of silver nanoclusters, providing important contributions to understanding the nanoclusters and their photophysical behaviors.

[Influence of paraspinal muscle degeneration and postoperative Roussouly classification restoration on mechanical complications in female patients with degenerative scoliosis after surgery]

Objective: To investigate the impact of lumbar paraspinal muscle degeneration and postoperative failure to restore ideal Roussouly classification on the occurrence of mechanical complications (MC) following long-segment spinal correction surgery in female patients with degenerative scoliosis (DS). Methods: The clinical data of 72 female DS patients who underwent long-segment spinal correction surgery in Gulou Hospital from June 2017 to November 2021 were retrospectively analyzed. According to whether restoring the ideal Roussouly classification after surgery, the patients were divided into R group(recovery group) (n=51) and N group(non-recovery group) (n=21). According to whether mechanical complications occurred after operation within two years, the patients were divided into MC (mechanical complications)group (n=24) and NMC(non-mechanical complications) group (n=48). The RM group (n=14) experienced mechanical complications in the R group, while the RN group (n=37) did not. The NM group (n=10) experienced mechanical complications in the N group, while the NN group (n=11) did not.Radiographic assessment included Sagittal parameters of spine and pelvis, standardized cross-sectional area (SCSA) and fat infiltration rate (FI%) of paraspinal muscle at each lumbar disc level. Results: The age of DS patients in this study was (61.4±6.2) years.The incidence of MC was 33.33%(n=24)in all patients. The incidence of MC was 27.45%(n=14)in group R and 47.62%(n=10) in group N. The correction amount of pelvic tilt angle (PT) (-11.62°±10.06° vs -7.04°±8.45°, P=0.046) and T1 pelvic angle(TPA)(-12.88°±11.23° vs -7.31°±9.55°, P=0.031)during surgery were significantly higher in MC group compared to the NMC group. In group R, the FI% of paraspinal muscles in each lumbar segment of patients with postoperative MC was higher than that in patients without MC (P<0.05). In the R and N groups, there was no significant difference inthe SCSA of the lumbar paravertebral muscles between patients with postoperative MC and those without MC at each level (all P>0.05). Multivariate logistic regression analysis showed that the average FI% of lumbar PSM was correlated with the occurrence of MC after spinal fusion in DS patients.The average FI% of lumbar PSM≥22.63% was a risk factors for MC after spinal fusion (P=0.010,OR=1.088, 95%CI:1.020-1.160). Conclusions: Female DS patients with higher degree of preoperative paraspinal muscle degeneration have a higher incidence of postoperative mechanical complications. For these patients,.there is still a higher risk of mechanical complications after surgery even if the ideal Roussouly classification is restored after surgery.

A Silver Nanocluster Assembled by a Superatomic Building Unit

A unique assembly of a two-electron superatom, [Ag10{S2P(OiPr)2}8], as a primary building unit in the construction of a supramolecule [Ag10{S2P(OiPr)2}8]2(μ-4,4'-bpy) through a 4,4'-bipyridine (4,4'-bpy) linker is reported. This approach is facilitated by an open site in the structure that allows for effective pairing. The assembled structure demonstrates a minimal solvatochromic shift across organic solvents with variable polarities, highlighting the influence of self-assembly on the photophysical properties of silver nanoclusters.

[Effect of different observations on evaluation of cosmetic shoulder balance in adolescent idiopathic scoliosis patients with thoracic curve]

Objective: To investigate the correlations between cosmetic and radiographic parameters of shoulder balance, as well as the variations in cosmetic shoulder balance observed from different perspectives, among patients with adolescent idiopathic scoliosis (AIS) characterized by thoracic curves. Methods: A total of 43 patients with thoracic curves treated from July to October in 2022 in Nanjing Drum Tower Hospital were recruited in this study. There were 9 males and 34 females with a mean age of (14.3±1.5) years. All participants underwent comprehensive radiographic assessments and were photographed both from posterior and anterior views, focusing on the shoulder region as well as a higher level (maintaining a consistent vertical distance of 180 cm from the ground). Six cosmetic parameters were measured on the photographs: shoulder angle(α1), axilla angle(α2), shoulder area index 1(SAI1), shoulder area index 2 (SAI2), inner shoulder height (SHi) and outer shoulder height (SHo). Eight radiographic parameters were measured on the radiographs: radiographic shoulder height difference (RSHD), first rib angle (FRA), clavicle-rib cage intersection (CRCI), coracoid process height (CPH), T1 tilt, clavicle angle(CA), clavicle chest cage angle difference (CCAD) and Cobb angle. Differences among bilateral cosmetic indicators from different perspectives were analyzed and compared, and their correlation with bilateral radiographic indicators was studied. Results: There was no significant differences between anterior cosmetic parameters and posterior cosmetic parameters at the same level of observation(all P>0.05). However, when observing SHi, SHo, α1, and α2 at the shoulder level, it became evident that they exhibited significantly higher values compared to the corresponding higher level on the same side of the patients' bodies. This contrast was observed in both the dorsal [SHo: (0.11±1.20) cm vs (-0.44±1.39) cm, P=0.005; SHi: (0.64±0.86) cm vs (0.32±0.56) cm, P=0.003; α1:-0.47°±2.27° vs -0.77°±2.49°, P=0.014; α2:-3.06°±3.23° vs -2.21°±3.03°, P=0.034] and ventral [SHo: (0.12±1.29) cm vs (-0.48±1.35) cm, P=0.007; SHi: (0.61±0.88) cm vs (0.30±0.59) cm, P=0.006; α1:-0.46°±2.18° vs -0.69°±2.35°, P=0.018; α2:-3.26°±3.12° vs -2.05°±2.97°, P=0.029] aspects of the patients. SHi and SHo were more sensitive to this difference of height. The correlation coefficients between radiographic parameters and cosmetic aspects at the shoulder level varied from 0.374 to 0.767. Similarly, the correlation coefficients between radiographic parameters and cosmetic factors at the higher level ranged from 0.273 to 0.579 (all P<0.05). Conclusions: The cosmetic parameters had significant difference between different perspective of observation, the cosmetic parameters are needed to be observed at the shoulder level in the evaluation of patients' shoulder balance.

Hydride-Containing Pt-doped Cu-rich Nanoclusters: Synthesis, Structure, and Electrocatalytic Hydrogen Evolution

A structurally precise hydride-containing Pt-doped Cu-rich nanocluster [PtH2 Cu14 {S2 P(Oi Pr)2 }6 (CCPh)6 ] (1) has been synthesized. It consists of a bicapped icosahedral Cu14 cage that encapsulates a linear PtH2 unit. Upon the addition of two equivalents of CF3 COOH to 1, two hydrido clusters are isolated. These clusters are [PtHCu11 {S2 P(Oi Pr)2 }6 (CCPh)4 ] (2), which is a vertex-missing Cu11 cuboctahedron encaging a PtH moiety, and [PtH2 Cu11 {S2 P(Oi Pr)2 }6 (CCPh)3 ] (3), a distorted 3,3,4,4,4-pentacapped trigonal prismatic Cu11 cage enclosing a PtH2 unit. The electronic structure of 2, analyzed by Density Functional Theory, is a 2e superatom. The electrocatalytic activities of 1-3 for hydrogen evolution reaction (HER) were compared. Notably, Cluster 2 exhibited an exceptionally excellent HER activity within metal nanoclusters, with an onset potential of -0.03 V (at 10 mA cm-2 ), a Tafel slope of 39 mV dec-1 , and consistent HER activity throughout 3000 cycles in 0.5 M H2 SO4 . Our study suggests that the accessible central Pt site plays a crucial role in the remarkable HER activity and may provide valuable insights for establishing correlations between catalyst structure and HER activity.

Nanotribological Characteristics of the Al Content of AlxGa1-xN Epitaxial Films

The nanotribological properties of aluminum gallium nitride (AlxGa1-xN) epitaxial films grown on low-temperature-grown GaN/AlN/Si substrates were investigated using a nanoscratch system. It was confirmed that the Al compositions played an important role, which was directly influencing the strength of the bonding forces and the shear resistance. It was verified that the measured friction coefficient (μ) values of the AlxGa1-xN films from the Al compositions (where x = 0.065, 0.085, and 0.137) were in the range of 0.8, 0.5, and 0.3, respectively, for Fn = 2000 μN and 0.12, 0.9, and 0.7, respectively, for Fn = 4000 μN. The values of μ were found to decrease with the increases in the Al compositions. We concluded that the Al composition played an important role in the reconstruction of the crystallites, which induced the transition phenomenon of brittleness to ductility in the AlxGa1-xN system.

Reduced-Dose Rivaroxaban Is Associated with Lower All-Cause Mortality in Older Patients with Nonvalvular Atrial Fibrillation

BACKGROUND

Reduced-dose rivaroxaban (10 mg) was used in the J-ROCKET AF trial, demonstrating safety in the Asian population. It remains unclear whether treatment with reduced-dose versus full-dose rivaroxaban (20 mg/15 mg) is associated with all-cause mortality in older patients with nonvalvular atrial fibrillation. Proposed: To evaluate the effects of reduced-dose rivaroxaban on all-cause mortality in patients over 85.

METHODS

We retrospectively enrolled medical records representing the period from October 2012 to November 2016. The 2 × 2 factorial design incorporated age (≥85 vs. <85) and rivaroxaban use (reduced vs. full dose). The primary study outcomes were all-cause and cardiac-related mortality.

RESULTS

The study enrolled 2386 patients with a mean age of 76.6 ± 10.4 years; 51.8% were male. In the ≥85 group (n = 593), the reduced-dose subgroup had lower all-cause (5.3% vs. 10.6%, p = 0.02) and cardiac-related mortality (1.9% vs. 5.1%, p = 0.04), whereas the younger patients receiving reduced-dose rivaroxaban had higher all-cause mortality (3.7% vs. 1.8%, p = 0.01) but no difference in cardiac-related mortality (1.2% vs. 0.7%, p = 0.33). The rate of hospitalization for heart failure was significantly lower in the elderly group with reduced-dose rivaroxaban (7.2% vs. 15.7%, p < 0.01) but not in the younger group. After adjusting for confounders in the older group, treatment with reduced-dose rivaroxaban was associated with lower risk of all-cause mortality (adjusted HR (aHR): 0.40, 95% CI: 0.21-0.74, p < 0.01) and hospitalization for heart failure (aHR: 0.54, 95% CI: 0.29-0.99, p = 0.05). No associations were found between rivaroxaban dose and cardiac-related mortality in either group, nor between younger age and any outcome.

CONCLUSIONS

Reduced-dose rivaroxaban was associated with lower risks of all-cause mortality and hospitalization for heart failure in older patients with nonvalvular atrial fibrillation. Future studies can investigate the effect of reduced-dose rivaroxaban on prognoses in elderly individuals ≥85 years in the west.

Spin independence of the strongly enhanced effective mass in ultra-clean SiGe/Si/SiGe two-dimensional electron system

The effective mass at the Fermi level is measured in the strongly interacting two-dimensional (2D) electron system in ultra-clean SiGe/Si/SiGe quantum wells in the low-temperature limit in tilted magnetic fields. At low electron densities, the effective mass is found to be strongly enhanced and independent of the degree of spin polarization, which indicates that the mass enhancement is not related to the electrons' spins. The observed effect turns out to be universal for silicon-based 2D electron systems, regardless of random potential, and cannot be explained by existing theories.

The Interplay Effect and Mitigations with Cyclotron and Linac Proton Beam Scanning for Lung SBRT

PURPOSE/OBJECTIVE(S)

To evaluate the impact of different types of pencil beam scanning proton accelerators and spot sizes on interplay effects, mitigations, and plan quality for lung cancer patients treated with SBRT.

MATERIALS/METHODS

Twenty lung cancer patients (ten peripheral and ten central tumors) treated in our institution with photon SBRT were selected to represent varying tumor volumes and respiratory motion amplitudes for this retrospective study. The respiratory motion amplitude ranged from 0.1 to 1.0 cm with compression. For each patient, plans were created using: 1) cyclotron-generated proton beams (CPB) (σ: 2.7-7.0 mm); 2) linear accelerator proton beams (LPB) (σ: 2.9-5.5 mm); and 3) linear accelerator proton minibeams (LPMB) (σ: 0.9-3.9 mm). Plans were robustly optimized on the GTV using each individual 4DCT phase. Single-filed optimization (SFO) plans were the first attempt, and if the plan quality did not meet the dosimetric requirement, multi-field optimization (MFO) was used. MFO plans were created for all patients for comparison. For each patient, all plans were normalized to have the same dose to 99% of the GTV. Interplay effects were evaluated for ten scenarios of treatment delivery starting in ten breathing phases using machine generic time models and a constant breathing period of 4 seconds. Volumetric repainting (VR) was performed 2-6 times for each plan. To assess plan quality in the nominal scenario, we compared the conformity index (CI), R50, and the percentage of lung volume receiving 20 Gy (RBE) (V20Gy). CI is defined as the ratio of the 100% isodose volume to the GTV. R50 is defined as the 50% isodose volume divided by the GTV. Dmax and V18Gy of the proximal bronchial tree (PBT) were evaluated for central tumors.

RESULTS

Twelve of 20 plans can be optimized sufficiently with SFO. In interplay effect evaluation, the mean V100%RX values of the GTV were 99.42±0.6%, 97.52±3.9%, and 94.49±7.3%for CPB, LPB, and LPMB plans respectively. After VR 2/3/5 times, the V100%RX values were improved (on average) by 0.13%/1.84%/4.63% for CPB/LPB/LPMB plans. The delivery time for VR plans was the lowest for LPB plans, while delivery time for LPMB was on average 1 minute longer than CPB plans. VR showed no effect on lung V20Gy, Dmax and V18Gy of the PBT. SFO plans were more robust against the interplay effect compared with MFO plans for LPB and LPMB. Average CIs of 1.88±0.4, 1.79±0.4, and 1.75±0.4; average R50s of 7.99±4.0, 6.68±3.0, and 5.70±2.6; and average lung V20Gy values of 2.81±1.5, 2.26±1.3, and 1.85±1.1 were obtained for CPB, LPB, and LPMB plans, respectively. Dmax and V18Gy of the PBT decreased with decreasing spot sizes.

CONCLUSION

LPMB, with the smallest spot size, produced superior plan quality. In the absence of VR, proton machines with large spot sizes generated more robust plans against interplay effects. VR improved the plan robustness against interplay effects for modalities with small spot sizes and fast energy changes, preserving the low dose sparing aspect of the LPMB, even when motion is included.

Investigation of the Relationship between Aperture Use for Treating Small and Shallow Brain Lesions in Proton Therapy with Different Spot Size Variations in Three Proton Therapy Systems

PURPOSE/OBJECTIVE(S)

To compare plan quality among standard vs. aperture-based Intensity-Modulated Proton Therapy (IMPT) using cyclotron-generated proton beams (CPB), linear accelerator proton beams (LPB), and linear accelerator proton minibeams (LPMB) for multiple brain metastases.

MATERIALS/METHODS

Fifty-five brain lesions from twenty patients were planned with three different spot size ranges using CPBs (σ: 2.7-7.0 mm) and compared against LPBs (σ: 2.9-5.5 mm), and LPMBs (σ: 0.9-3.9 mm). Apertures with a diameter of 0.3 cm were applied to beams irradiating all tumors < 1 cm3 in volume and any tumor < 2.5 cm depth in the patient and compared against the same patient plans containing no apertures. All plans were optimized with the multi-field optimization (MFO) technique using the Monte Carlo algorithm. Dose coverage to each lesion for each proton plan was set to 99% of the GTV receiving the prescription (Rx) dose for all plans. Robustness with ±2 mm setup uncertainty and ±2% range uncertainty was included in robust evaluation using V100%Rx > 95% of the GTV. Conformity index (CI) and gradient index (GI) were used to analyze the effect of apertures vs. no apertures (standard) for each IMPT plan type. CI was defined as the volume of the 100% isodose line divided by the volume of the GTV + 2 mm expansion to account for robust planning. The Wilcoxon signed rank test was utilized to determine the statistical significance of dosimetric results compared between aperture-based and standard IMPT plans.

RESULTS

When apertures were implemented in the treatment planning for all shallow and small brain lesions, shallow brain tumors showed the most prominent improvement in conformity and gradient index. A 6.7% difference in average conformity was calculated for standard vs. aperture-based plans for LPMBs, followed by a 5.3% improvement for CPBs. Improvement in gradient index for standard vs. aperture-based plans was significant for both shallow and deeper tumors for CPB and LPB plan types, as shown in Table 1 below. CPB and LPB plan gradient indices were statistically significant for comparing aperture-based vs. standard IMPT plans.

CONCLUSION

We successfully quantified plan quality and evaluated results for aperture- vs. standard IMPT plans using CPBs, LPBs, and LPMBs for brain metastases. Plan quality improves the greatest with apertures applied to beams irradiating shallow tumors. Apertures may not be necessary for small, deeper tumors with IMPT.

Hydride Doping Effects on the Structure and Properties of Eight-Electron Rh/Ag Superatoms: The [RhHx@Ag21-x{S2P(OnPr)2}12] (x = 0-2) Series

Three hitherto unknown eight-electron rhodium/silver alloy nanoclusters, [RhAg₂₁{S₂P(OⁿPr)₂}₁₂] (1), [RhHAg₂₀{S₂P(OⁿPr)₂}₁₂] (2), and [RhH₂Ag₁₉{S₂P(OⁿPr)₂}₁₂] (3), have been isolated and fully characterized. Cluster 1 contains a regular Rh@Ag₁₂ icosahedral core, whereas 2 and 3 exhibit distorted RhH@Ag₁₂ and RhH₂@Ag₁₂ icosahedral cores. The single-crystal neutron structure of 2 located the encapsulated hydride at the center of an enlarged RhAg₃ tetrahedron. A similar position was found by neutron diffraction for one of the hydrides in 3, whereas the other hydride is trigonally coordinated to Rh and an elongated Ag-Ag edge. The solid-state structures of 1-3 possess C₁ symmetry due to the asymmetric arrangement of the surrounding capping Ag atoms. Our investigation shows that the insertion of one hydride dopant provokes the elimination of one capping silver atom on the cluster surface, resulting in the general formula [RhH_x@Ag_21-x{S₂P(OⁿPr)₂}₁₂] (x = 0-2), which maintains the same number of cluster electrons as well as neutral charge. Clusters 1-3 exhibit an intense emission band in the NIR region. Contrarily to their PdAg₂₁ and PdHAg₂₀ relatives, the 4d orbitals of the encapsulated heterometal are somewhat involved in the optical processes.

A heteroleptic fused bi-cuboctahedral Cu21S2 cluster

A new dicationic cluster, [Cu₂₁S₂{S₂CNⁿBu₂}₉(C₂Ph)₆]²⁺, where the Cu21S2 kernel consists of two S@Cu₁₂ cuboctahedra sharing a triangular Cu₃ face is reported. Its waist part is bridged by three dithiocarbamate ligands, each in a hexaconnective, hexametallic (μ₃, μ₃) coordination pattern, an unprecedented feature in Cu nanocluster chemistry.

Recent progress in dichalcophosphate coinage metal clusters and superatoms

Atomically precise clusters of group 11 metals (Cu, Ag, and Au) attract considerable attention owing to their remarkable structure and fascinating properties. One of the unique subclasses of these clusters is based on dichalcophosphate ligands of [(RO)₂PE₂]^- type (E = S or Se, and R = alkyl). These ligands successfully stabilise the most diverse Cu, Ag, and Au clusters and superatoms, spanning from simple ones to amazing assemblies featuring unusual structural and bonding patterns. It is noteworthy that such complicated clusters are assembled directly from cheap and simple reagents, metal(I) salts and dichalcophosphate anions. This reaction, when performed in the presence of a hydride or other anion sources, or foreign metal ions, results in hydrido- or anion-templated homo- or heteronuclear structures. In this feature article, we survey the recent advances in this exciting field, highlighting the powerful synthetic capabilities of the system "a metal(I) salt - [(RO)₂PX₂]^- ligands - a templating anion or borohydride" as an inexhaustible platform for the creation of new atomically precise clusters, superatoms, and nanoalloys.

Galvanic replacement-induced introduction of a heteroligand into bimetallic and trimetallic nanoclusters

Heteroleptic 8-electron silver-rich alloy nanoclusters, [Au@Au₄Ag₁₂(dtp)₇(PPh₃)₄]²⁺ (1) and [Pt@Au₄Ag₁₁(dtp)₇(PPh₃)₄] (2), were successfully synthesized via a galvanic replacement reaction of 1,1-dithiolate-protected M@Ag₂₀ (M = Au and Pt) nanoclusters with Au(I)-phosphine salts, leading to the alteration of the cluster nuclearity and geometry of shell skeletons but retaining the same 8-electron count.

Superatom Pruning by Diphosphine Ligands as a Chemical Scissor

A two-electron silver superatom, [Ag₆{S₂P(OⁱPr)₂}₄(dppm)₂] (1), was synthesized by adding dppm (bis(diphenylphosphino)methane) into [Ag₂₀{S₂P(OⁱPr)₂}₁₂] (8e). It was characterized by single-crystal crystallography, multinuclear NMR spectroscopy, electrospray ionization-mass spectrometry, density functional theory (DFT), and time-dependent DFT calculations. The added dppm ligands, which carry out the nanocluster-to-nanocluster transformation, act as a chemical scissor to prune the nanocluster geometrically from an icosahedron-based Ag₂₀ nanocluster (NC) to an octahedral Ag₆ NC and electronically from eight-electron to two-electron. Eventually, dppm was involved in the protective shell to form a new heteroleptic NC. The temperature-dependent NMR spectroscopy confirms its fluxional behavior, showing the fast atomic movement at ambient temperature. Compound 1 exhibits a bright yellow emission under UV irradiation at ambient temperature with a quantum yield of 16.3%. This work demonstrates a new methodology to achieve nanocluster-to-nanocluster transformation via stepwise synthesis.

Hydride-containing 2-Electron Pd/Cu Superatoms as Catalysts for Efficient Electrochemical Hydrogen Evolution

The first hydride-containing 2-electron palladium/copper alloys, [PdHCu₁₁ {S₂ P(Oⁱ Pr)₂ }₆ (C≡CPh)₄ ] (PdHCu₁₁ ) and [PdHCu₁₂ {S₂ P(Oⁱ Pr)₂ }₅ {S₂ PO(Oⁱ Pr)} (C≡CPh)₄ ] (PdHCu₁₂ ), are synthesized from the reaction of [PdH₂ Cu₁₄ {S₂ P(Oⁱ Pr)₂ }₆ (C≡CPh)₆ ] (PdH₂ Cu₁₄ ) with trifluoroacetic acid (TFA). X-ray diffraction reveals that the PdHCu₁₁ and PdHCu₁₂ kernels consist of a central PdH unit encapsulated within a vertex-missing Cu₁₁ cuboctahedron and complete Cu₁₂ cuboctahedron, respectively. DFT calculations indicate that both PdHCu₁₁ and PdHCu₁₂ can be considered as axially-distorted 2-electron superatoms. PdHCu₁₁ shows excellent HER activity, unprecedented within metal nanoclusters, with an onset potential of -0.05 V (at 10 mA cm^-2 ), a Tafel slope of 40 mV dec^-1 , and consistent HER activity during 1000 cycles in 0.5 M H₂ SO₄ . Our study suggests that the accessible central Pd site is the key to HER activity and may provide guidelines for correlating catalyst structures and HER activity.

Unusual core engineering on a copper hydride nanoball

A neutral polyhydrido copper cluster, [Cu₂₇H₁₅{S₂CNⁿBu₂}₁₂] (abbreviated as [Cu₂₇H₁₅]), was prepared by the reaction of dithiocarbamates (dtc), Cu(I) salts and NaBH₄. The isolated cluster provides insights into core engineering, demonstrating its novel ability to reversibly add or remove one copper atom from the cluster core. Single-crystal X-ray analysis reveals that the new core-shell structure exhibits a Cu₂₄ rhombicuboctahedral outer cage and an inner Cu₃ triangular kernel. The two core-shell clusters, [Cu₂₇H₁₅{S₂CNⁿBu₂}₁₂] and previously published [Cu₂₈H₁₅(S₂CNⁿBu₂)₁₂]⁺ (abbreviated as [Cu₂₈H₁₅]⁺), are only differentiated by one copper atom in their inner core. Importantly, we demonstrate core engineering with the controllable reversible transition between an irregular Cu₄ tetrahedron and a Cu₃ triangle, whilst maintaining their outer Cu₂₄ shell intact. The 15 hydride atoms in [Cu₂₇H₁₅], coordinated in three different modes, are co-incident with the hydride positions in [Cu₂₈H₁₅]⁺. The degradation of [Cu₂₇H₁₅] in solution or the addition of one eq. of Cu(I) ions leads to the conversion of [Cu₂₇H₁₅] into [Cu₂₈H₁₅]⁺, while the reverse transformation can be achieved by the addition of either formic acid or a reducing agent to [Cu₂₈H₁₅]⁺. A dicationic species was observed in the ESI mass spectrum, and the composition is formulated as [Cu₅₆H₃₀(S₂CNⁿBu₂)₂₄]²⁺, a dimer of [Cu₂₇H₁₅(S₂CNⁿBu₂)₁₂ + Cu⁺]₂²⁺. The dimeric species was further explored by DFT calculations, suggesting that the lowest energy structure consists of a [Cu₂₈H₁₅]⁺ and a [Cu₂₇H₁₅] cluster connected through one Cu⁺ atom bridge. As a result, [Cu₂₇H₁₅] is considered an intermediate species in the formation of the more stable [Cu₂₈H₁₅]⁺ nanoball.

Left ventricular hypertrophy detection using electrocardiographic signal

Left ventricular hypertrophy (LVH) indicates subclinical organ damage, associating with the incidence of cardiovascular diseases. From the medical perspective, electrocardiogram (ECG) is a low-cost, non-invasive, and easily reproducible tool that is often used as a preliminary diagnosis for the detection of heart disease. Nowadays, there are many criteria for assessing LVH by ECG. These criteria usually include that voltage combination of RS peaks in multi-lead ECG must be greater than one or more thresholds for diagnosis. We developed a system for detecting LVH using ECG signals by two steps: firstly, the R-peak and S-valley amplitudes of the 12-lead ECG were extracted to automatically obtain a total of 24 features and ECG beats of each case (LVH or non-LVH) were segmented; secondly, a back propagation neural network (BPN) was trained using a dataset with these features. Echocardiography (ECHO) was used as the gold standard for diagnosing LVH. The number of LVH cases (of a Taiwanese population) identified was 173. As each ECG sequence generally included 8 to 13 cycles (heartbeats) due to differences in heart rate, etc., we identified 1466 ECG cycles of LVH patients after beat segmentation. Results showed that our BPN model for detecting LVH reached the testing accuracy, precision, sensitivity, and specificity of 0.961, 0.958, 0.966 and 0.956, respectively. Detection performances of our BPN model, on the whole, outperform 7 methods using ECG criteria and many ECG-based artificial intelligence (AI) models reported previously for detecting LVH.