Reversible solvent interactions with UiO-67 metal-organic frameworks

The utility of UiO-67 Metal-Organic Frameworks (MOFs) for practical applications requires a comprehensive understanding of intermolecular host-guest MOF-analyte interactions. To investigate intermolecular interactions between UiO-67 MOFs and complex molecules, it is useful to evaluate the interactions with simple polar and non-polar analytes. This problem is approached by investigating the interactions of polar (acetone and isopropanol) and non-polar (n-heptane) molecules with functionalized UiO-67 MOFs via temperature programmed desorption mass spectrometry and temperature programmed Fourier transform infrared spectroscopy. We find that isopropanol, acetone, and n-heptane bind reversibly and non-destructively to UiO-67 MOFs, where MOF and analyte functionality influence relative binding strengths (n-heptane ≈ isopropanol > acetone). During heating, all three analytes diffuse into the internal pore environment and directly interact with the μ3-OH groups located within the tetrahedral pores, evidenced by the IR response of ν(μ3-OH). We observe nonlinear changes in the infrared cross sections of the ν(CH) modes of acetone, isopropanol, and n-heptane following diffusion into UiO-67. Similarly, acetone's ν(C=O) infrared cross section increases dramatically when diffused into UiO-67. Ultimately, this in situ investigation provides insights into how individual molecular functional groups interact with UiO MOFs and enables a foundation where MOF interactions with complex molecular systems can be evaluated.

[Safety and efficacy of transcatheter aortic valve replacement using the "All in One" single artery/vessel technique]

Objective: To explore the safety and efficacy of transcatheter aortic valve replacement (TAVR) using the "All in One" single-artery/vessel technique. Methods: This is a retrospective study. A total of 30 consecutive patients underwent TAVR using the single artery/vascular technique in Beijing Anzhen Hospital from August to December 2021 were included. Baseline clinical data, operative situation, postoperative outcomes, and incidence of adverse events during hospitalization and at one month post TAVR were analyzed. Results: Mean age was (72.6±9.7) years, 16 were male patients, STS score was (4.73±3.12)%. Four patients were diagnosed as isolated aortic regurgitation (all with tricuspid aortic valves), and 26 patients were diagnosed as aortic stenosis (AS), 10 of whom with tricuspid aortic valves and 16 of whom with bicuspid aortic valves. The single-vessel technique was applied in 3 aortic stenosis cases; the single-artery technique was applied in 27 cases. Echocardiography was performed immediately after procedure and results showed no or trace perivalvular leak in 27 cases and small perivalvular leak in 3 cases; the mean aortic transvalvular gradient of 26 AS patients decreased from (50.4±16.0) mmHg (1 mmHg=0.133 kPa) to (9.4±3.2) mmHg (P<0.001). The procedure time was (64.8±18.9) min. There were no intraoperative death, valve displacement, conversion to surgery, coronary artery occlusion in all 30 patients. There were no major cardiac adverse events such as myocardial infarction or stroke occurred during hospitalization or at follow-up. One-month follow-up echocardiography indicated prosthesis works well. The symptoms were significantly alleviated, and the Kansas City Cardiomyopathy Score (KCCQ score) of all patients increased from 48.1±18.4 to 73.5±17.6 (P<0.001). Conclusions: TAVR using the single artery/vessel technique is safe and feasible. This technique is related to reduced access complications and worthy of wide application.

[Feasibility study of using bridging temporary permanent pacemaker in patients with high-degree atrioventricular block after TAVR]

Objective: To determine the feasibility of using temporary permanent pacemaker (TPPM) in patients with high-degree atrioventricular block (AVB) after transcatheter aortic valve replacement (TAVR) as bridging strategy to reduce avoidable permanent pacemaker implantation. Methods: This is a prospective observational study. Consecutive patients undergoing TAVR at Beijing Anzhen Hospital and the First Affiliated Hospital of Zhengzhou University from August 2021 to February 2022 were screened. Patients with high-degree AVB and TPPM were included. Patients were followed up for 4 weeks with pacemaker interrogation at every week. The endpoint was the success rate of TPPM removal and free from permanent pacemaker at 1 month after TPPM. The criteria of removing TPPM was no indication of permanent pacing and no pacing signal in 12 lead electrocardiogram (EGG) and 24 hours dynamic EGG, meanwhile the last pacemaker interrogation indicated that ventricular pacing rate was 0. Routinely follow-up ECG was extended to 6 months after removal of TPPM. Results: Ten patients met the inclusion criteria for TPPM, aged (77.0±11.1) years, wirh 7 females. There were 7 patients with third-degree AVB, 1 patient with second-degree AVB, 2 patients with first degree AVB with PR interval>240 ms and LBBB with QRS duration>150 ms. TPPM were applied on the 10 patients for (35±7) days. Among 8 patients with high-degree AVB, 3 recovered to sinus rhythm, and 3 recovered to sinus rhythm with bundle branch block. The other 2 patients with persistent third-degree AVB received permanent pacemaker implantation. For the 2 patients with first-degree AVB and LBBB, PR interval shortened to within 200 ms. TPPM was successfully removed in 8 patients (8/10) at 1 month without permanent pacemaker implantation, of which 2 patients recovered within 24 hours after TAVR and 6 patients recovered 24 hours later after TAVR. No aggravation of conduction block or permanent pacemaker indication were observed in 8 patients during follow-up at 6 months. No procedure-related adverse events occurred in all patients. Conclusion: TPPM is reliable and safe to provide certain buffer time to distinguish whether a permanent pacemaker is necessary in patients with high-degree conduction block after TAVR.

The diagnosis and treatment of central retinal artery occlusion with severe cardio-cerebrovascular disease: a case report

BACKGROUND

Central retinal artery occlusion (CRAO) is an acute eye disease that seriously damages vision. Patients with CRAO often have a combination of various cardio-cerebrovascular diseases (CCVDs), and CRAO patients often ignore their cardio-cerebrovascular disorders because of their ocular symptoms. In addition, there are few reports about CRAO patients with CCVDs received effective interventions implemented. We report the diagnosis and treatment of a Chinese CRAO patient with CCVD who received timely multidisciplinary interventional therapy to provide ideas for clinical ophthalmologists in the diagnosis and treatment of similar diseases.

CASE DESCRIPTION

A 76-year-old male patient, who had previously been diagnosed with hypertension, was admitted to hospital due to a sudden decrease in vision in his right eye for >2 days with a severe headache. After fundus photography, he was diagnosed with CRAO in the right eye. His cerebral angiography revealed multiple stenoses at arteries of his neck and brain included the right ophthalmic artery. Neurosurgery was attempted to perform a thrombolysis of the right ophthalmic artery while performing the angiography, but failed to find the opening of the right ophthalmic artery. However, through electrocardiogram (ECG) monitoring during the operation, we found that the patient had frequent ventricular premature beats, so the Department of Cardiology performed coronary arteriography for him which revealed severe stenosis of the left anterior descending (LAD) artery. The cardiologists performed a percutaneous coronary intervention (PCI) at the same time as the coronary angiography. Some 2 months later, the patient was admitted to the Neurosurgery Department to implant stent at the left vertebral artery. After stent implantation, his headache symptom improved significantly and his right eye vision improved.

CONCLUSIONS

Through timely cerebral angiography and ophthalmic examinations, the patient was diagnosed with CRAO combined with CCVD, and after received multidisciplinary interventional therapy, the patient's right eye vision and headache symptom improved and more severe cardio-cerebrovascular adverse events were avoided. In treating CRAO patients, in addition to aggressive eye treatment, the systemic cardio-cerebrovascular situation of each patient should also be assessed, a timely diagnosis made, and effective interventions implemented to reduce morbidity- and mortality-related cardio-cerebrovascular events.

Cholesterol affects the relationship between albumin and major adverse cardiac events in patients with coronary artery disease: a secondary analysis

We aimed to examine whether the efficacy of the risk of poor prognosis in patients with coronary artery disease is jointly affected by total cholesterol and baseline serum albumin in a secondary analysis of previous study. We analyzed the data of 204 patients from October 2014 to October 2017 for newly diagnosed stable CAD. The outcome was major adverse cardiac events (MACE; defined as all cause mortality, non fatal myocardial infarction, and non fatal stroke). The median duration of follow-up was 783 days. Multivariable COX model was performed to revalidate the relationship between the sALB and MACE and interaction tests were conducted to find the effects of total cholesterol on their association. A total of 28 MACE occurred among the 204 participants. The risk of MACE varied by baseline serum albumin and total cholesterol. Specifically, lower serum albumin indicated higher risk of MACE (HR 3.52, 95% CI 1.30-9.54), and a test for interaction between baseline serum albumin and total cholesterol on MACE was significant (P = 0.0005). We suggested that baseline serum albumin and total cholesterol could interactively affect the risk of poor prognosis of patients with coronary artery diseases. Our findings need to be confirmed by further randomized trials.

[Diagnostic value of MDM2 RNA in situ hybridization in atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma]

Objective: To investigate the value of MDM2 RNA in situ hybridization (RNA-ISH) in diagnosing atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) and dedifferentiated liposarcoma (DDL). Methods: A total of 26 ALT/WDL/DDLs diagnosed from March 2017 to May 2019 in West China Hospital, Sichuan University, Chengdu, China and 18 control cases were included. MDM2 RNA-ISH was performed on all samples and compared with the fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) regarding their performance in detecting MDM2. Results: All samples were detected successfully using the three methods. Among 26 ALT/WDL/DDLs, all cases showed MDM2 amplification and positivity for MDM2 RNA-ISH (26/26, 100%). Twenty-four (24/26, 92.3%) of the 26 tested cases were positive for MDM2 IHC while two of them were negative. Eighteen control cases were all negative for MDM2 FISH and RNA-ISH, and 15 (15/18) cases were negative for MDM2 IHC. The sensitivity and specificity of RNA-ISH were both 100%, and those of MDM2 IHC were 92.3% and 83.3%, respectively. Diffuse staining was identified in all MDM2 RNA-ISH positive ALT/WDL/DDLs, but identified in only 8/24 (33.3%) of the MDM2 IHC positive cases. Among the 11 ALT/WDL/DDL samples evaluated on tissue microarray, the positive rate of MDM2 RNA-ISH was 100% with diffuse staining in all cases. The positive rate of MDM2 IHC was 9/11 while only 1 of the 9 cases showed diffuse staining. The result of MDM2 RNA-ISH was identical to that of MDM2 FISH and was overall consistent with that of MDM2 IHC (Kappa=0.763, P<0.001). Conclusions: In ALT/WDL/DDLs, results of MDM2 RNA-ISH are highly consistent with those of FISH. MDM2 RNA-ISH is more sensitive and more specific and has more diffuse positive signals than the IHC. The findings indicate that MDM2 RNA-ISH is highly valuable for the diagnosis and differential diagnosis of ALT/WDL/DDLs.

Identifying UiO-67 Metal-Organic Framework Defects and Binding Sites through Ammonia Adsorption

Ammonia is a widely used toxic industrial chemical that can cause severe respiratory ailments. Therefore, understanding and developing materials for its efficient capture and controlled release is necessary. One such class of materials is 3D porous metal-organic frameworks (MOFs) with exceptional surface areas and robust structures, ideal for gas storage/transport applications. Herein, interactions between ammonia and UiO-67-X (X: H, NH₂ , CH₃ ) zirconium MOFs were studied under cryogenic, ultrahigh vacuum (UHV) conditions using temperature-programmed desorption mass spectrometry (TPD-MS) and in-situ temperature-programmed infrared (TP-IR) spectroscopy. Ammonia was observed to interact with μ₃ -OH groups present on the secondary building unit of UiO-67-X MOFs via hydrogen bonding. TP-IR studies revealed that under cryogenic UHV conditions, UiO-67-X MOFs are stable towards ammonia sorption. Interestingly, an increase in the intensity of the C-H stretching mode of the MOF linkers was detected upon ammonia exposure, attributed to NH-π interactions with linkers. These same binding interactions were observed in grand canonical Monte Carlo simulations. Based on TPD-MS, binding strength of ammonia to three MOFs was determined to be approximately 60 kJ mol^-1 , suggesting physisorption of ammonia to UiO-67-X. In addition, missing linker defect sites, consisting of H₂ O coordinated to Zr⁴⁺ sites, were detected through the formation of nNH₃ ⋅H₂ O clusters, characterized through in-situ IR spectroscopy. Structures consistent with these assignments were identified through density functional theory calculations. Tracking these bands through adsorption on thermally activated MOFs gave insight into the dehydroxylation process of UiO-67 MOFs. This highlights an advantage of using NH₃ for the structural analysis of MOFs and developing an understanding of interactions between ammonia and UiO-67-X zirconium MOFs, while also providing directions for the development of stable materials for efficient toxic gas sorption.

Two-Dimensional Zr/Hf-Hydroxamate Metal-Organic Frameworks

Novel two-dimensional kagome metal-organic frameworks with mononuclear Zr4+/Hf4+ nodes chelated by benzene-1,4-dihydroxamate linkers were synthesized. The MOFs, namely SUM-1, are chemically robust and kinetically favorable, as confirmed by theoretical and...

Rhamnolipid pretreatment enhances methane production from two-phase anaerobic digestion of waste activated sludge

In this work, a rhamnolipid (RL) pretreatment technology was proposed to promote methane production from two-phase anaerobic digestion of waste activated sludge. In the first phase (i.e., acidogenic phase), the WAS hydrolysis and acidogenesis were significantly enhanced after RL pretreatment for 4 day, under which the concentration of soluble protein and the short-chain fatty acids (SCFA) in the presence of RL at 0.04 g/g TSS was respectively 2.50 and 5.02 times higher than that without RL pretreatment. However, methane production was inhibited in the presence of RL. In the second phase (i.e., methanogenic phase), batch biochemical methane potential tests suggested that the addition of RL is effective in promoting anaerobic methane production. With an increase of RL dosage from 0 to 0.04 g/g TSS, the cumulative methane yield increased from 100.42 ± 3.01 to 168.90 ± 5.42 mL. Although the added RL could be utilized to produce methane, it was not the major contributor to the enhancement of methane yield. Further analysis revealed that total cumulative yield from the entire two-phase anaerobic digestion (sum of the yield of the acidogenic phase and methanogenic phase) increased from 113.42 ± 3.56 to 164.18 ± 5.20 mL when RL dosage increased from 0 to 0.03 g/g TSS, indicating that the addition of RL induced positive effect on the methane production of the entire two-phase anaerobic digestion. The enzyme activity analysis showed that although higher dosages of RL still inhibited the microorganisms related to methanogenesis to some extends in the methanogenic phase, the inhibitory effect was significantly weakened compared to the acidogenic phase. Microbial analysis revealed that RL reduced the abundance of Candidatus_Methanofastidiosum sp. while increased the abundance of Methanosaeta sp., causing the major methanogenesis pathway to change from hydrogenotrophic to aceticlastic. Moreover, the community of hydrolytic microbes and acidogens was shifted in the direction that is conducive to hydrolysis-acidogenesis. The findings reported not only expand the application field of RL, but also may provide supports for sustainable operation of wastewater treatment plants (WWTPs).

Tuning the Lewis acidity of metal-organic frameworks for enhanced catalysis

The kinetics of hydrolysis of dimethyl nitrophenyl phosphate (DMNP), a simulant of the nerve agent Soman, was studied and revealed transition metal salts as catalysts. The relative rates of DMNP hydrolysis by zirconium and hafnium chlorides are in accordance with their Lewis acidity. In situ conversion of zirconium chloride to zirconium oxy-hydroxide was identified as the key step. We propose a precursor-MOF activity relationship.

Atom-by-Atom Evolution of the Same Ligand-Protected Au21, Au22, Au22Cd1, and Au24 Nanocluster Series

Atom-by-atom manipulation on metal nanoclusters (NCs) has long been desired, as the resulting series of NCs can provide insightful understanding of how a single atom affects the structure and properties as well as the evolution with size. Here, we report crystallizations of Au22(SAdm)16 and Au22Cd1(SAdm)16 (SAdm = adamantanethiolate) which link up with Au21(SAdm)15 and Au24(SAdm)16 NCs and form an atom-by-atom evolving series protected by the same ligand. Structurally, Au22(SAdm)16 has an Au3(SAdm)4 surface motif which is longer than the Au2(SAdm)3 on Au21(SAdm)15, whereas Au22Cd1(SAdm)16 lacks one staple Au atom compared to Au24(SAdm)16 and thus the surface structure is reconstructed. A single Cd atom triggers the structural transition from Au22 with a 10-atom bioctahedral kernel to Au22Cd1 with a 13-atom cuboctahedral kernel, and correspondingly, the optical properties are dramatically changed. The photoexcited carrier lifetime demonstrates that the optical properties and excited state relaxation are highly sensitive at the single atom level. By contrast, little change in both ionization potential and electron affinity is found in this series of NCs by theoretical calculations, indicating the electronic properties are independent of adding a single atom in this series. The work provides a paradigm that the NCs with continuous metal atom numbers are accessible and crystallizable when meticulously designed, and the optical properties are more affected at the single atom level than the electronic properties.

Heteroatom Tracing Reveals the 30-Atom Au-Ag Bimetallic Nanocluster as a Dimeric Structure

Understanding the formation of face-centered cubic (fcc) nanostructures at the atomic level remains a major task. With atomically precise nanoclusters (NCs) as model systems, herein we devised an atom-tracing strategy by heteroatom doping into Au₃₀(SR)₁₈ (SR = S-^tC₄H₉) to label the specific positions in M₃₀(SR)₁₈ NCs (M = Au/Ag), which clearly reveals the dimeric nature of M₃₀. Interestingly, the specific position is also consistent with the Ag-doping site in M₂₁(SR)₁₅. Electronic orbital analysis shows intrinsic orbital localization at the two specific positions in M₃₀, which are decisive to the electronic structure of M₃₀, regardless of Au or Ag occupancy. The fcc dimeric NC, which would not be discovered without Ag tracing, provides a possible explanation for the wide accessibility of nonsuperatomic Au-SR NCs.

Ship-in-a-Bottle Preparation of Long Wavelength Molecular Antennae in Lanthanide Metal-Organic Frameworks for Biological Imaging

While metal-organic frameworks (MOFs) have been identified as promising materials for sensitizing near-infrared emitting lanthanide ions (Ln³⁺) for biological imaging, long-wavelength excitation of such materials requires large, highly delocalized organic linkers or guest-chromophores. Incorporation of such species generally coincides with fewer Ln³⁺ emitters per unit volume. Herein, the excitation bands of ytterbium-based MOFs are extended to 800 nm via the postsynthetic coupling of acetylene units to form a high density of conjugated π-systems throughout MOF pores. The resulting long wavelength excitation/absorption bands are a synergistic property of the composite material as they are not observed in the individual organic components after disassociation of the MOFs, thus circumventing the need for large organic chromophores. We demonstrate that the long wavelength excitation and emission properties of these modified MOFs are maintained in the biological conditions of cell culture (aqueous environment, salts, heating), pointing toward their promising use for biological imaging applications.

Luminescence "Turn-On" Detection of Gossypol Using Ln3+-Based Metal-Organic Frameworks and Ln3+ Salts

Gossypol (Gsp), a natural toxin concentrated in cottonseeds, poses great risks to the safe consumption of cottonseed products, which are used extensively throughout the food industry. In this work, we report the first luminescence "turn-on" sensors for Gsp using near-infrared emitting lanthanide (Ln³⁺) materials, including Ln³⁺ MOFs and Ln³⁺ salts. We first demonstrate that the Yb³⁺ photoluminescence of a Yb³⁺ MOF, Yb-NH₂-TPDC, can be employed to selectively detect Gsp with a limit of detection of 25 μg/mL via a "turn-on" response from a completely nonemissive state in the absence of Gsp. The recyclability and stability of Yb-NH₂-TPDC in the presence of Gsp was demonstrated by fluorescence spectroscopy and PXRD analysis, respectively. A variety of background substances present in practical samples that would require Gsp sensing, such as refined cottonseed oil, palmitic acid, linoleic acid, and α-tocopherol, did not interfere with the Yb³⁺ photoluminescence signal. We further identified that the "turn-on" of Yb-NH₂-TPDC photoluminescence was due to the "antenna effect" of Gsp, as evidenced by spectroscopic studies and supported by computational analysis. This is the first report that Gsp can effectively sensitize Yb³⁺ photoluminescence. Leveraging this sensing mechanism, we demonstrate facile, highly sensitive, fast-response detection of Gsp using YbCl₃·6H₂O and NdCl₃·6H₂O solutions. Overall, we show for the first time that Ln³⁺-based materials are promising luminescent sensors for Gsp detection. We envision that the reported sensing approach will be applicable to the detection of a wide variety of aromatic molecules using Ln³⁺ compounds including MOFs, complexes, and salts.

Growth of ZIF-8 on molecularly ordered 2-methylimidazole/single-walled carbon nanotubes to form highly porous, electrically conductive composites

The combination of porosity and electrical conductivity in a single nanomaterial is important for a variety of applications. In this work, we demonstrate the growth of ZIF-8 on the surface of single-walled carbon nanotubes (SWCNTs). The growth mechanism was investigated and a molecularly ordered imidazole solvation layer was found to disperse SWCNTs and promote crystal growth on the sidewalls. The resultant ZIF-8/SWCNT composite demonstrates high microporosity and electrical conductivity. The ZIF-8/SWCNT composite displayed semiconducting electrical behavior and an increase in sensor sensitivity toward ethanol vapors versus pristine SWCNTs.

Near infrared excitation and emission in rare earth MOFs via encapsulation of organic dyes

We successfully demonstrate that metal-organic frameworks (MOFs) can be designed to be excited and emit within the biological diagnostic window (650-1450 nm). An isoreticular series of anionic rare earth MOFs with fcu topology was synthesized using 10 different rare earth elements (Y3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+) and common linear ditopic ligands. Five different cationic dye molecules were incorporated into the MOFs via ion exchange. When LDS 750, which exhibits low-energy absorption in the range 450-770 nm, is loaded into an Yb3+-MOF, it can be used as an antenna to sensitize the near-infrared (NIR) emission of Yb3+ centred at 980 nm.

Modulating the hierarchical fibrous assembly of Au nanoparticles with atomic precision

The ability to modulate nanoparticle (NP) assemblies with atomic precision is still lacking, which hinders us from creating hierarchical NP organizations with desired properties. In this work, a hierarchical fibrous (1D to 3D) assembly of Au NPs (21-gold atom, Au21) is realized and further modulated with atomic precision via site-specific tailoring of the surface hook (composed of four phenyl-containing ligands with a counteranion). Interestingly, tailoring of the associated counterion significantly changes the electrical transport properties of the NP-assembled solids by two orders of magnitude due to the altered configuration of the interacting π-π pairs of the surface hooks. Overall, our success in atomic-level modulation of the hierarchical NP assembly directly evidences how the NP ligands and associated counterions can function to guide the 1D, 2D, and 3D hierarchical self-assembly of NPs in a delicate manner. This work expands nanochemists' skills in rationally programming the hierarchical NP assemblies with controllable structures and properties.

Single-ligand exchange on an Au-Cu bimetal nanocluster and mechanism

An Au-Cu bimetallic nanocluster co-capped by selenolate and phosphine is obtained and its X-ray structure shows an icosahedral Au13 kernel surrounded by three CuSe2PPh2Py motifs and one CuSe3 motif, formulated as [Au13Cu4(PPh2Py)3(SePh)9]. Interestingly, a single-ligand exchange process is observed in the growth reaction, in which an [Au13Cu4(PPh2Py)4(SePh)8]+ intermediate is first formed, but a prolonged reaction leads to one PPh2Py ligand being selectively replaced by a PhSe-ligand. DFT simulations reveal that both steric hindrance and bond dissociation energy have great effects on the single-ligand exchange reaction as well as the thermodynamics, which help to understand the mechanism of the ligand exchange. Temperature-dependent UV-vis absorption and photoluminescence (PL) properties of the Au-Cu nanocluster imply that the optical properties are mainly contributed by the metal core. Femtosecond time-resolved pump-probe analysis maps out further details of the PL process.

[The impact of red blood cell distribution width on outcome of elective percutaneous coronary intervention in non-anemia patients]

Objective: Previous studies have revealed that the red blood cell distribution width (RDW) was associated with long-term prognosis in patients undergoing percutaneous coronary intervention (PCI). However, they did not exclude patients with anemia. This study, thus, investigated the association between RDW and prognosis in non-anemia patients. Methods: A total of 2 732 patients underwent elective PCI from July 2009 to September 2011 were enrolled in the study. These patients were divided into two groups based on their baseline median RDW levels: low RDW group (RDW<12.1%) and high RDW group (RDW≥12.1%). All the subjects were followed up for an average period of 18 months and the associations between baseline RDW levels and postoperative mortality were analyzed. Results: Patients in the high RDW group were elder and had more women than those in low RDW group. Most of them had prior history of hypertension, stroke, myocardial infarction, but few of them were current smokers. Subjects in the high RDW group had higher systolic blood pressure and total cholesterol levels, and lower erythrocyte mean corpuscular volume, hemoglobin level, estimated glomerular filtration rate level, and left ventricular ejection fraction. Moreover, more subjects in the high RDW group were combined with left main, ostial and chronic total occlusion lesion, and had a lower complete revascularization rate. The postoperative mortality was significantly higher in the high RDW group than that in the low RDW group (2.4% vs 0.6%, P<0.001). Multivariate Cox regression analysis revealed that preoperative high RDW level was an independent risk factor for postoperative mortality after adjustment of other factors (HR 3.930, 95%CI 1.600-9.656, P=0.003). Conclusion: High RDW might be a marker for the postoperative mortality in non-anemic patients undergoing elective PCI.

Molecular "surgery" on a 23-gold-atom nanoparticle

Compared to molecular chemistry, nanochemistry is still far from being capable of tailoring particle structure and functionality at an atomic level. Numerous effective methodologies that can precisely tailor specific groups in organic molecules without altering the major carbon bones have been developed, but for nanoparticles, it is still extremely difficult to realize the atomic-level tailoring of specific sites in a particle without changing the structure of other parts (for example, replacing specific surface motifs and deleting one or two metal atoms). This issue severely limits nanochemists from knowing how different motifs in a nanoparticle contribute to its overall properties. We demonstrate a site-specific "surgery" on the surface motif of an atomically precise 23-gold-atom [Au₂₃(SR)₁₆]^- nanoparticle by a two-step metal-exchange method, which leads to the "resection" of two surface gold atoms and the formation of a new 21-gold-atom nanoparticle, [Au₂₁(SR)₁₂(Ph₂PCH₂PPh₂)₂]⁺, without changing the other parts of the starting nanoparticle structure. This precise surgery of the nanocluster reveals the different reactivity of the surface motifs and the inner core: the least effect of surface motifs on optical absorption but a distinct effect on photoluminescence (that is, a 10-fold enhancement of luminescence after the tailoring). First-principles calculations further reveal the thermodynamically preferred reaction pathway for the formation of [Au₂₁(SR)₁₂(Ph₂PCH₂PPh₂)₂]⁺. This work constitutes a major step toward the development of atomically precise, versatile nanochemistry for the precise tailoring of the nanocluster structure to control its properties.

Silicon Nanoparticles with Surface Nitrogen: 90% Quantum Yield with Narrow Luminescence Bandwidth and the Ligand Structure Based Energy Law

Silicon nanoparticles (NPs) have been widely accepted as an alternative material for typical quantum dots and commercial organic dyes in light-emitting and bioimaging applications owing to silicon's intrinsic merits of least toxicity, low cost, and high abundance. However, to date, how to improve Si nanoparticle photoluminescence (PL) performance (such as ultrahigh quantum yield, sharp emission peak, high stability) is still a major issue. Herein, we report surface nitrogen-capped Si NPs with PL quantum yield up to 90% and narrow PL bandwidth (full width at half-maximum (fwhm) ≈ 40 nm), which can compete with commercial dyes and typical quantum dots. Comprehensive studies have been conducted to unveil the influence of particle size, structure, and amount of surface ligand on the PL of Si NPs. Especially, a general ligand-structure-based PL energy law for surface nitrogen-capped Si NPs is identified in both experimental and theoretical analyses, and the underlying PL mechanisms are further discussed.

Usefulness of normal saline for sealing the needle track after CT-guided lung biopsy

AIM

To determine whether the use of normal saline for sealing the needle track can reduce the incidence of pneumothorax and chest tube placement after computed tomography (CT)-guided lung biopsy.

MATERIALS AND METHODS

A prospective, randomised, controlled trial enrolling 322 patients was conducted. All patients were randomly assigned to one of two groups: those in whom the needle track was not sealed with normal saline (n=161, Group A) and those who did receive normal saline (n=161, Group B). CT-guided biopsy was performed with coaxial technique. Normal saline, which ranged from 1-3 ml, was injected while the trocar needle was being withdrawn. Patient characteristics, lesion, and procedure variables were analysed as potential risk variables for occurrence of pneumothorax and chest tube placement.

RESULTS

The incidence of pneumothorax was 26.1% in Group A and 6.2% in Group B (p<0.001). Nine patients in Group A and one patient in Group B required chest tube placement (p=0.010). Using multiple logistic regression analysis, smaller lesion size, greater needle-pleural angle, longer lesion-pleural distance, presence of emphysema, and no sealing the needle track with normal saline were significantly associated with an increased risk of pneumothorax, and that the latter three factors were also associated with an increased risk of pneumothorax requiring chest tube placement.

CONLUSION

Normal saline for sealing the needle track significantly reduces the incidence of pneumothorax and prevents subsequent chest tube placement after CT-guided lung biopsy.

Association between the FGB gene polymorphism and ischemic stroke: a meta-analysis

To clarify the relationship between the β-fibrinogen (FGB) genetic polymorphism (-148C>T) and ischemic stroke, we identified studies by searching PubMed, EMBASE, and the Chinese National Knowledge Infrastructure (CKNI) databases. Data from eligible studies were extracted and subjected to meta-analysis. Publication bias was tested using a funnel plot. We identified 12 independent case-control studies containing 1536 ischemic stroke patients and 1329 control subjects. Our results showed that the -148C>T polymorphism in the FGB gene was associated with an increased risk of ischemic stroke [CC vs (TT+CT), odds ratio = 0.69, 95% confidence interval (CI) = 0.59-0.80, P < 0.0001; TT vs (CC+CT), odds ratio = 3.01, 95%CI = 1.29-7.05; P = 0.01; T vs C, odds ratio = 1.32, 95%CI = 1.15-1.52, P < 0.0001] by a meta-analysis. The results of our meta-analysis suggested that the -148C>T polymorphism in the FGB gene is a susceptibility marker of ischemic stroke.

Cytotoxic pheophorbide-related compounds from Clerodendrum calamitosum and C. cyrtophyllum

Three pheophorbide-related compounds (1-3) were isolated from the leaves and stems of Clerodendrum calamitosum. The methyl ester of 3 (6) and the known (10S)-hydroxypheophytin a (7) also were isolated from leaves of the related plant Clerodendrum cyrtophyllum. Compounds 1 and 6 were isolated for the first time as naturally occurring products from a plant source. All structures were elucidated by detailed spectroscopic analysis. Biological evaluation showed that 1 and 2 exhibited strong cytotoxicity against human lung carcinoma (A549), ileocecal carcinoma (HCT-8), kidney carcinoma (CAKI-1), breast adenocarcinoma (MCF-7), malignant melanoma (SK-MEL-2), ovarian carcinoma (1A9), and epidermoid carcinoma of the nasopharynx (KB), and its etoposide- (KB-7d), vincristine- (KB-VCR), and camptothecin-resistant (KB-CPT) subclones. Compound 3 was less cytotoxic than 1 and 2. Compounds 4-6, the methyl esters of 1-3, showed strongly increased cytotoxicity compared with the parent acids. Interestingly, 6 was the most active derivative among these compounds. Compound 7 was inactive.

Sexual harassment in the Chinese workplace. Attitudes toward and experiences of sexual harassment among workers in Taiwan

This study employed a questionnaire survey method to examine the characteristics of sexual harassment experiences and the dynamics of attitudes toward sexual harassment among male and female workers in Taipei. An occupationally representative sample of male and female workers was recruited to participate in the survey. The study found that 1 in 4 workers in Taipei experienced some sort of sexual harassment in the workplace: 36% (n = 493) of the surveyed women and 13% (n = 415) of the surveyed men reported experiencing workplace sexual harassment. The most frequently reported type of sexual harassment is unwanted sexual jokes/comments, followed by unwanted deliberate body contact, and unwanted requests/pressure for a date. The major source of sexual harassment came from coworkers of the opposite sex; the majority of the alleged victims attributed the sexual harassment incident to insensitivity of the initiator. The study considers three explanations of sexual harassment among Chinese workers: the victimblame/trivialization model, the natural/biological explanation, and the power/manipulation model. The study found no consistent relationship between the self-rated attitudes toward sexual harassment and the self-reported experiences of sexual harassment.

Gamna-gandy bodies of the spleen depicted by unenhanced CT: report of two cases

We report two cases of Gamna-Gandy bodies (GGB) of the spleen, confirmed by MRI, in which unenhanced CT depicted multiple faint high-attenuation spots in the spleens. These spots were considered to represent the calcifications in GGB. CT and MRI reflect the different compositions of GGB. In a very limited number of patients with portal hypertension, unenhanced CT may detect GGB, and this entity should be included in the differential diagnosis of calcified foci of the spleen.

Von Meyenburg complexes of the liver: imaging findings

PURPOSE

Our purpose was to present imaging findings of six cases proven or supposed to be von Meyenburg complexes (VMCs) with a basis of reviewing the pathologic literature and to describe imaging points for the diagnosis of typical VMC along with its differential diagnosis.

METHOD

Six cases were diagnosed as VMC of the liver with imaging modalities (one had histopathologic proof). Both ultrasound (US) and CT were available for all cases, and MRI was used for three cases. Follow-up with US, CT and/or MRI was performed in five cases.

RESULTS

US detected varying abnormalities of the livers in four cases. CT and MRI revealed multiple or numerous intrahepatic tiny (usually < 5 mm) cystoid lesions in all of the cases. The lesions were scattered throughout the livers, and some of them were located more frequently adjacent to the medium-sized portal veins than to the hepatic veins of similar size on CT. Moreover, some lesions were apparently located in the subcapsular areas (up to the hepatic capsules). They were usually irregular in shape and showed no enhancement but increased in number by approximately 80-150% after administration of intravenous contrast medium. The T2-weighted MR images and MR cholangiopancreatography showed the lesions to be much more apparent and to be more numerous than T1-weighted images did. Follow-up of five cases with imaging modalities did not show remarkable change of the lesions.

CONCLUSION

Despite our limited experience, VMC lesions seem to show some CT and MR features different from those of other multiple small hepatic lesions. They presented as multiple or numerous intrahepatic tiny cystoid lesions usually with irregular contour, scattered throughout the liver up to the subcapsular areas, and were detected in far greater number by enhanced CT or T2-weighted MR images than by unenhanced CT or T1-weighted images. They showed no remarkable change on long term follow-up imaging. We propose that a diagnosis of typical VMC could be made after analyzing CT or MR images carefully with good understanding of its pathologic basis, but imaging follow-up is necessary in oncology patients.

[A study on the multiple factorial causation of hepatoma among young patients]

Pathogenetic significance of major risk factors to primary hepatoma among young people was investigated through a case-control study. The analysis of single-factor showed that there was close relationship between HBV infection, family history of hepatoma and the primary hepatocellular carcinoma among young people, with an OR 25.3. Multiple-factorial analysis indicated that the effect of HBV infection far exceeded other risk factors in the pathogenesis of primary hepatoma, suggesting the HBV infection might be a major cause of primary hepatoma among young people.