Monoarsine-protected icosahedral cluster [Au13(AsPh3)8Cl4]+: comparative studies on ligand effect and surface reactivity with its stibine analogue.

Ligand shells of gold nanoclusters play important roles in regulating their molecular and electronic structures. However, the similar but distinct impacts of the homologous analogues of the protecting ligands remain elusive. The C2v symmetric monoarsine-protected cluster [Au13(AsPh3)8Cl4]+ (Au13As8) was facilely prepared by direct reduction of (Ph3As)AuCl with NaBH4. This cluster is isostructural with its previously reported stibine analogue [Au13(SbPh3)8Cl4]+ (Au13Sb8), enabling a comparative study between them. Au13As8 exhibits a blue-shifted electronic absorption band, and this is probably related to the stronger π-back donation interactions between the Au13 core and AsPh3 ligands, which destabilize its superatomic 1P and 1D orbitals. In comparison to the thermodynamically less stable Au13Sb8, Au13As8 achieves a better trade-off between catalytic stability and activity, as demonstrated by its excellent catalytic performance towards the aldehyde-alkyne-amine (A3) coupling reaction. Moreover, the ligand exchange reactions between Au13As8 with phosphines, as exemplified by PPh3 and Ph2P(CH2)2PPh2, suggest that Au13As8 may be a good precursor cluster for further cluster preparation through the "cluster-to-cluster" route.

Ag22 Nanoclusters with Thermally Activated Delayed Fluorescence Protected by Ag/Cyanurate/Phosphine Metallamacrocyclic Monolayers through In-Situ Ligand Transesterification.

The composition of protection monolayer exerts great influence on the molecular and electronic structures of atomically precise monolayer protected metal nanoclusters. Four isostructural Ag/cyanurate/phosphine metallamacrocyclic monolayer protected Ag22 nanoclusters are synthesized by kinetically controlled in-situ ligand formation-driven strategy. These eight-electron superatomic silver nanoclusters feature an unprecedented interfacial bonding structure with diverse E-Ag (E=O/N/P/Ag) interactions between the Ag13 core and metallamacrocyclic monolayer, and displays thermally activated delayed fluorescence (TADF), benefiting from their distinct donor-acceptor type electronic structures. This work not only unmasks a new core-shell interface involving cyanurate ligand but also underlines the significance of high-electron-affinity N-heterocyclic ligand in synthesizing TADF metal nanoclusters. This is the first mixed valence Ag0/I nanocluster with TADF characteristic.

Expression and prognostic relevance of CRP, PCT, and ll-15 in patients with postoperative infection due to spinal injury.

C-reactive protein (CRP), procalcitonin (PCT), interleukin-15 (ll-15) expression and prognostic relevance were analyzed in patients with postoperative infection due to spinal injury. For this purpose, a total of 169 cases of spinal injury patients who underwent surgical treatment from July 2021 to July 2022 were selected, and the patients were divided into the uninfected group (148 cases), infected group (21 cases) according to the presence or absence of infection after surgery. Looking at the site of infection in both groups, the levels of CRP, PCT, and ll-15 in the two groups were detected using an enzyme-linked immunosorbent assay, and the expression of the three in postoperative infection of spinal injury and the correlation with prognosis were analyzed. Results showed that compared with the uninfected group, the infected group had higher levels of CRP, PCT, and ll-15, which were different (P < 0.05). There were no significant differences in the CRP levels between the superficial infection of the incision and the deep infection of the incision as well as other systemic infection populations at 1 d after surgery (P >0.05). CRP levels were higher in the group with deep infection of the incision as well as other systemic infections compared to the group with superficial infection at 3D and 7d after surgery (P < 0.05). There were no significant differences in the level of PCT between patients with superficial infection of the incision and those with deep infection of the incision as well as other systemic infections at 1 d after surgery (P > 0.05). The level of PCT was higher in the population with deep infection of incision as well as other systemic infections compared to the population with superficial infection at 3D and 7d after the operation (P<0.05). There were no statistically significant differences in the levels of ll-15 between patients with superficial infection of the incision and those with deep infection of the incision as well as other systemic infections at 1 D postoperatively (P>0.05). At 3D and 7d postoperatively, compared to the population with superficial incisions, the population with deep incisions as well as other systemic infections had higher levels of ll-15 with statistical significance (P < 0.05). CRP and PCT showed a positive correlation (r=7.192, P=0.001). CRP, ll-15 showed a positive correlation (r = 5.231, P = 0.001). PCT, ll-15 showed a positive correlation (r=9.029, P=0.001). CRP, PCT, ll-15 levels are closely related to postoperative infection in spinal injury. CRP, PCT, ll-15 showed high expression in postoperative infection of spinal injury and compared with the infection of the superficial part of the incision, the infection of the deep part of the incision, other systems have higher levels of CRP, PCT, ll-15. Moreover, CRP, PCT, and ll-15 were significantly associated with prognosis.

Facet Sagittal Orientation: Possible Role in the Pathology of Degenerative Lumbar Spinal Stenosis.

STUDY DESIGN: A retrospective case-control study. OBJECTIVE: This study aimed to elucidate the association between facet joint orientation and degenerative lumbar spinal stenosis (DLSS). SUMMARY OF BACKGROUND DATA: Many studies have demonstrated the relationship between sagittal facet orientation and degenerative lumbar spondylolisthesis. However, the associations between facet orientation and DLSS have rarely been studied. METHODS: Ninety-one age-matched and sex-matched patients with DLSS (LSS group) and 91 control participants were consecutively enrolled. Their lumbar facet angles and the dural sac cross-sectional area at L2-L3, L3-L4, L4-L5, and L5-S1 were measured using axial magnetic resonance imaging. The intersection angle of the midsagittal line of the vertebra to the facet line represents the orientation of the facet joint. RESULTS: The facet angles on the left side or right side of the LSS group were significantly smaller than the respective ones of the control group. Outcomes of the groups revealed significantly and consistently increasing facet angles from L2-L3 to L5-S1. The dural sac cross-sectional area of the LSS group had significantly smaller measurements values than that of the control group at L2-L3, L3-L4, L4-L5, and L5-S1. CONCLUSION: Sagittalization of lumbar facet joints was considered to be a risk factor for DLSS and may play a role in the pathology of DLSS. LEVEL OF EVIDENCE: 3.

[Establishment of rat hypophyseal compression model and changes in its postoperative biological characteristics].

OBJECTIVE: To establish a rat model of hypophyseal compression and observe and analyze the changes in its biological characteristics after operation. METHODS: The rats were subjected to compression of the pituitary gland by stuffing the autologous muscular tissue into the hypophyseal fossa. The postoperative mortality of the rats was recorded and the volume of the hypophyeseal fossa, body weight, daily food intake, water intake, urine volume and urine specific gravity were measured. RESULTS: Rat models of the hypophyseal compression model were successfully established by this procedure, which resulted in an increase of the volume of hypophyseal fossa by 35%. Rapid body weight loss occurred within 5 weeks after the operation (by as much as 31% on day 10). The rats exhibited recovery of appetite after 2 weeks, but their food intake was still less than that in the control group. Manifestations of central diabetes insipidus occurred gradually, which were especially obvious at 2 weeks and persisted afterwards, and at this time point, significant increment of urine volume (55.4-/+15.9 vs 18.5-/+5.8 ml) and lowered urine gravity (1.011-/+0.004 vs 1.036-/+0.006) were observed. CONCLUSION: Rat models of hypophyseal compression can be established successfully by the described procedure, and the compression results in alteration of the rats' metabolic behaviors, which may differ from the effects of hypophysectomy and damage of pituitary stalk.