We developed a fully closed nano-focus X-ray source using carbon nanotube (CNT) field emitters. The nano-focus X-ray source includes a fully vacuum-sealed CNT Electron-gun (E-gun) tube and ...E-beam-focusing modules consisting of electrostatic and magnetic lenses, facilitating very compact and high-resolution X-ray imaging. The paste-printed CNT emitters were prepared in a small pattern as an electron source, and the entire components, including the CNT emitter module, Cu tubes, collimators, and transmissive anode target, were specially brazed at an elevated temperature, resulting in a very compact E-gun tube. The CNT emitter showed a stable and reliable emission current with its density of over 300 mA/cm 2 even in the vacuum-sealed E-gun tube. With the anode grounded and the CNT emitter module biased to negative high voltages, we achieved a considerably magnified x-ray image of a several hundred nanometer resolution. The fully vacuum-sealed CNT E-gun tube along with the magnetic lens module can offer much more compact, easily maintainable, high-resolution X-ray imaging compared with conventional open-type thermionic X-ray sources.
Acquired somatic mutations in hematopoietic stem and progenitor cells (clonal hematopoiesis or CH) are associated with advanced age, increased risk of cardiovascular and malignant diseases, and ...decreased overall survival. These adverse sequelae may be mediated by altered inflammatory profiles observed in patients with CH. A pro-inflammatory immunologic profile is also associated with worse outcomes of certain infections, including SARS-CoV-2 and its associated disease Covid-19. Whether CH predisposes to severe Covid-19 or other infections is unknown. Among 525 individuals with Covid-19 from Memorial Sloan Kettering (MSK) and the Korean Clonal Hematopoiesis (KoCH) consortia, we show that CH is associated with severe Covid-19 outcomes (OR = 1.85, 95%=1.15-2.99, p = 0.01), in particular CH characterized by non-cancer driver mutations (OR = 2.01, 95% CI = 1.15-3.50, p = 0.01). We further explore the relationship between CH and risk of other infections in 14,211 solid tumor patients at MSK. CH is significantly associated with risk of Clostridium Difficile (HR = 2.01, 95% CI: 1.22-3.30, p = 6×10
) and Streptococcus/Enterococcus infections (HR = 1.56, 95% CI = 1.15-2.13, p = 5×10
). These findings suggest a relationship between CH and risk of severe infections that warrants further investigation.
As hospitals cater to elderly and vulnerable patients, a high mortality rate is expected if a coronavirus disease 2019 (COVID-19) outbreak occurs. Consequently, policies to prevent the spread of ...COVID-19 in hospital settings are essential. This study was conducted to investigate how effectively national and international guidelines provide recommendations for infection control issues in hospitals. After selecting important issues in infection control, we performed a systematic review and analysis of recommendations and guidelines for preventing COVID-19 transmission within medical institutions at national and international levels. We analyzed guidelines from the World Health Organization, Centers for Disease Control and Prevention, European Centre for Disease Prevention and Control, and Korea Disease Control and Prevention Agency. Recent guidelines do not provide specific solutions to infection control issues. Therefore, efforts need to be made to devise consistent advice and guidelines for COVID-19 control.
Reports detailing the clinical characteristics, viral load, and outcomes of patients with normal initial chest CT findings are lacking. We sought to compare the differences in clinical findings, ...viral loads, and outcomes between patients with confirmed COVID-19 who initially tested negative on chest CT (CT negative) with patients who tested initially positive on chest CT (CT positive). The clinical data, viral loads, and outcomes of initial CT-positive and CT-negative patients examined between January 2020 and April 2020 were retrospectively compared. The efficacy of viral load (cyclic threshold value Ct value) in predicting pneumonia was evaluated using receiver operating characteristic (ROC) curve and area under the curve (AUC). In total, 128 patients underwent initial chest CT (mean age, 54.3 ± 19.0 years, 50% male). Of those, 36 were initially CT negative, and 92 were CT positive. The CT-positive patients were significantly older (P < .001) than the CT-negative patients. Only age was significantly associated with the initial presence of pneumonia (odds ratio, 1.060; confidence interval (CI), 1.020-1-102; P = .003). In addition, age (OR, 1.062; CI, 1.014-1.112; P = .011), fever at diagnosis (OR, 6.689; CI, 1.715-26.096; P = .006), and CRP level (OR, 1.393; CI, 1.150-1.687; P = .001) were significantly associated with the need for O2 therapy. Viral load was significantly higher in the CT-positive group than in the CT-negative group (P = .017). The cutoff Ct value for predicting the presence of pneumonia was 27.71. Outcomes including the mean hospital stay, intensive care unit admission, and O2 therapy were significantly worse in the CT-positive group than in the CT-negative group (all P < .05). In conclusion, initially CT-negative patients showed better outcomes than initially CT-positive patients. Age was significantly associated with the initial presence of pneumonia, and viral load may help in predicting the initial presence of pneumonia.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cyclin-dependent kinase 4/6 inhibitor (CDK4/6) therapy plus endocrine therapy (ET) is an effective treatment for patients with hormone receptor-positive/human epidermal receptor 2-negative metastatic ...breast cancer (HR+/HER2- MBC); however, resistance is common and poorly understood. A comprehensive genomic and transcriptomic analysis of pretreatment and post-treatment tumors from patients receiving palbociclib plus ET was performed to delineate molecular mechanisms of drug resistance.
Tissue was collected from 89 patients with HR+/HER2- MBC, including those with recurrent and/or metastatic disease, receiving palbociclib plus an aromatase inhibitor or fulvestrant at Samsung Medical Center and Seoul National University Hospital from 2017 to 2020. Tumor biopsy and blood samples obtained at pretreatment, on-treatment (6 weeks and/or 12 weeks), and post-progression underwent RNA sequencing and whole-exome sequencing. Cox regression analysis was performed to identify the clinical and genomic variables associated with progression-free survival.
Novel markers associated with poor prognosis, including genomic scar features caused by homologous repair deficiency (HRD), estrogen response signatures, and four prognostic clusters with distinct molecular features were identified. Tumors with TP53 mutations co-occurring with a unique HRD-high cluster responded poorly to palbociclib plus ET. Comparisons of paired pre- and post-treatment samples revealed that tumors became enriched in APOBEC mutation signatures, and many switched to aggressive molecular subtypes with estrogen-independent characteristics. We identified frequent genomic alterations upon disease progression in RB1, ESR1, PTEN, and KMT2C.
We identified novel molecular features associated with poor prognosis and molecular mechanisms that could be targeted to overcome resistance to CKD4/6 plus ET.
ClinicalTrials.gov, NCT03401359. The trial was posted on 18 January 2018 and registered prospectively.
Field electron emission from carbon nanotubes (CNT) is preceded by the transport of electrons from the cathode metal to emission sites. Specifically, a supporting layer indispensable for adhesion of ...CNT paste emitters onto the cathode metal would impose a potential barrier, depending on its work function and interfacial electron transport behaviors. In this paper, we investigated the supporting layer of silicon carbide and nickel nanoparticles reacted onto a Kovar alloy (Fe–Ni–Co) cathode substrate, which has been adopted for reliable CNT paste emitters. The X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and electrical conductivity measurements showed that the reaction of silicon carbide and nickel nanoparticles on the Kovar metal strongly depends upon the post-vacuum-annealing conditions and can be classified into two procedures of a diffusion-induced reaction (DIR) and a diffusion-limited reaction (DLR). The prolonged annealing at 750 °C for 5 h before the main annealing of the CNT paste emitters at 800 °C for 5 min led to the DIR that has enhanced the Ni silicide phase and a lower potential barrier for the interfacial electron transport, resulting in increased and weakly temperature-dependent field electron emission from the CNT paste emitters. On the other hand, the DLR with only the main anneal of the CNT paste emitters at 800 °C for 5 min gave rise to a higher potential barrier for the electron transport and so lower and strongly temperature-dependent field electron emission. From the results of the interfacial electron transport for the DIR and DLR mechanisms in the CNT paste emitters, we concluded that the ambient temperature dependency of field electron emission from CNT tips in the moderate range of up to 400 °C, still controversial, is mainly attributed to the supporting layer of the CNT emitter rather than its intrinsic electron emission.
Polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC) hydrogels containing various CMC concentration of 2 to 10 wt% are prepared using cyclic freezing/thawing and subsequent
γ
-ray irradiation to ...evaluate the effect of CMC content on cell growth rate of the hydrogels. A 3-D porous network structure is successfully formed
via
physical and chemical crosslinking. The pore size and the metronidazole drug release rate of the PVA/CMC hydrogels increase with raising the CMC concentration from 2 to 10 wt%, however, the structural integrity is severely damaged. The highest compressive strength of 99.2 ± 9.6 kPa and the fastest cell growth determined by scratch assay and enzyme-linked immunosorbent assay are observed for the irradiated PVA/6 wt% CMC hydrogels, indicating that they are highly suitable for wound dressing requiring fast regeneration.
OBJECTIVE Hypoalbuminemia is known to be independently associated with postoperative acute kidney injury (AKI). However, little is known about the association between the preoperative serum albumin ...level and postoperative AKI in patients undergoing brain tumor surgery. The authors investigated the incidence of AKI, impact of preoperative serum albumin level on postoperative AKI, and death in patients undergoing brain tumor surgery. METHODS The authors retrospectively reviewed the electronic medical records and laboratory results of 2363 patients who underwent brain tumor surgery between January 2008 and December 2014. Postoperative AKI was defined according to Kidney Disease: Improving Global Outcomes Definition and Staging (KDIGO). Multivariate logistic regression analysis was used to identify demographic, preoperative laboratory, and intraoperative factors associated with AKI development. Cox proportional hazards models were used to investigate the adjusted odds ratio and hazard ratio for the association between preoperative serum albumin level and outcome variables. RESULTS The incidence of AKI was 1.8% (n = 43) using KDIGO criteria. The incidence of AKI was higher in patients with a preoperative serum albumin level < 3.8 g/dl (3.5%) than in those with a preoperative serum albumin level ≥ 3.8 g/dl (1.2%, p < 0.001). The overall mortality was also higher in the former than in the latter group (5.0% vs 1.8%, p < 0.001). After inverse probability of treatment-weighting adjustment, a preoperative serum albumin level < 3.8 g/dl was also found to be associated with postoperative AKI (OR 1.981, 95% CI 1.022-3.841; p = 0.043) and death (HR 2.726, 95% CI 1.522-4.880; p = 0.001). CONCLUSIONS The authors' results demonstrated that a preoperative serum albumin level of < 3.8 g/dl was independently associated with AKI and mortality in patients undergoing brain tumor surgery.
This study investigated the association between atherosclerosis and systemic inflammation markers, specifically the C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ...neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), in healthy middle-aged adults.
A retrospective cross-sectional study was conducted on a total of 1264 Korean adults aged 40-65. We assessed these inflammatory markers and carotid metrics, such as carotid intima-media thickness (cIMT), plaque number (PN), plaque stenosis score (PSS), and plaque score (PS), using linear regression, logistic regression, and receiver operating characteristic analysis.
In males, the ESR and CRP were significantly correlated with the PN (
< 0.001 and
= 0.048, respectively). The ESR was correlated with the PN in females (
= 0.004). The NLR and PLR both correlated with the PS in males (
< 0.001 and
= 0.015, respectively) and females (
= 0.015 and
= 0.023, respectively). The odds ratio for the NLR as a risk factor for increased cIMT was 1.15 (95% confidence interval CI, 1.03-2.15) for males and 1.05 (95% CI, 1.01-1.29) for females. The AUC for the NLR and PLR as a predictor for the PS showed significance in both men and women.
Inflammatory markers, particularly the NLR and PLR, demonstrate a correlation with carotid atherosclerosis. Both the NLR and PLR hold potential as valuable surrogate markers for carotid atherosclerosis. To further substantiate their predictive efficacy, further prospective studies are needed.
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