Hasil untuk "Microscopy"

M. Karnovsky

The lead hydroxide stain of Watson (1958) used for increasing contrast in thin sections for electron microscopy has found acceptance in many laboratories. However, this stain has an unfortunate tendency to form precipitates (probably of lead carbonate (5)) on exposure to the air, thus contaminating the sections and irritating the observer. This drawback has led to the development of several modifications (2, 3) of the original method of staining and the use of ingenious devices (4, 5) for preventing exposure to air and consequent precipitate formation. We offer the following alternative methods which, we believe, are simpler to perform than those hitherto described. They have the additional advantages mentioned below. The methods are based on the observation that highly alkaline solutions of lead salts (pH > 11.5) yield relatively stable solutions which stain rapidly and intensely, thus obviating the hazard of precipitation to a marked degree. The methods have these additional advantages: the staining solutions are easily and rapidly prepared, are simply stored, and are stable for long periods of time. Furthermore, they can be efficiently used, many grids being treated simultaneously, without excessive precautions being taken against lead carbonate precipitation. Finally, "difficult" material, embedded in media which characteristically yield rather low contrast, such as epoxide resins, can be rapidly and easily stained. "C lean" preparations, of high contrast, are routinely obtained. As will be discussed later, it is thought that in these highly alkaline staining solutions lead is present as an hydroxide complex anion (plumbite ion) and that this anion is responsible for the staining. The methods of preparation are based on this hypothesis. Two methods for preparing the staining solutions have been found useful:

P. So, C. Dong, B. Masters et al.

Chris Xu, W. Zipfel, J. Shear et al.

P. Hinterdorfer, Werner Baumgartner, H. Gruber et al.

B. Stipe, M. Rezaei, W. Ho

S. Brenner, R. Horne

P. Hinterdorfer, Y. Dufrêne

G. Shtengel, J. Galbraith, C. Galbraith et al.

Jixin Cheng, X. S. Xie

H. Shroff, C. Galbraith, J. Galbraith et al.

S. Ruzin

K. Fujita

J. Fiala

Vebjorn Ljosa, Katherine L. Sokolnicki, Anne E Carpenter

E. Hoover, J. Squier

Minbiao Ji, D. Orringer, C. Freudiger et al.

Xurong Liu, Jipang Zhan, Jingwen Zou et al.

Abstract Introduction Surgical excision is the standard treatment for basal cell carcinoma (BCC). For locally advanced BCC (laBCC) not suitable for surgery or radiotherapy, Hedgehog pathway inhibitors (HHIs) such as sonidegib are important options. Clinical observations have shown that sonidegib may lead to pigmentation and scarring, which can affect treatment evaluation. We evaluated the efficacy and safety of sonidegib in Chinese patients with laBCC and examined discrepancies between clinical/dermoscopic assessments and pathological findings, including posttreatment pathological changes. Methods This single-center retrospective study included 54 patients with laBCC treated with sonidegib 200 mg/day for ≥ 3 months (October 2022–July 2025). Response assessment integrated VISIA-based planimetric lesion-area regression, standardized dermoscopy, and dermoscopy-guided multi-site biopsy as the pathological gold standard. The primary endpoint was objective response rate (ORR); secondary endpoints included disease control rate (DCR) and safety. Results At 3 months, ORR was 87% (complete response [CR] 48%; partial response [PR] 39%), and DCR was 100%. Pathology showed complete clearance in 48.1% and residual tumor in 51.9%, with six cases showing apparent histologic subtype shifts. Dermoscopy in patients with complete remission still demonstrated a high false-positive rate (branching blood vessels 53.8%, blue-gray dots 61.5%), leading to decreased diagnostic specificity. Adverse events occurred in 81.5% of patients; 70.4% reported multiple events, most commonly muscle cramps (66.7%), dysgeusia (59.3%), and alopecia (55.6%). All events were grade 1–3, and no patient discontinued treatment as a result of toxicity. Conclusion In this real-world Chinese laBCC cohort, sonidegib produced a clinically meaningful response with a favorable safety profile. However, clinical and dermoscopic assessments showed substantial false positives due to posttreatment changes; pathological biopsy remains essential to confirm tumor clearance. Advanced noninvasive imaging (e.g., reflectance confocal microscopy) may further improve monitoring. Prospective studies with longer follow-up are warranted.

Ali Ashraf Derakhshan, Ali Akbar Zinatizadeh, Ali Rostami et al.

Abstract This research offers a simple and convenient strategy for surface decoration of polyurethane sponge foam through the covalent attachment of 5,5-dimethylhydantoin as an N-halamine precursor using 1,6-hexamethylene diisocyanate as a crosslinking agent. After hypochlorite bleach treatment, the N-H bonds in the 5,5-dimethylhydantoin moieties on the polyurethane sponge foam surface change into N-Cl bonds. This modification enhances antibacterial performance against both Gram-positive and Gram-negative bacteria. The washing stability of the prepared Cl-DMH-PUSF substrates was studied after 20 rinsing cycles using the DPD tablet test. The results showed that no active chlorine was released from the Cl-DMH-PUSF substrate after multiple washing processes, implying the strong stability of the active chlorine on the N-halamine surface. To characterize the synthesized antiseptic samples, field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis were applied. FESEM images revealed a collection of needle-shaped nanoparticles on the Cl-DMH-PUSF surface, which could act as a needle in contact with bacteria and contribute to pathogen death. This approach is innovative as it uses commercial polyurethane sponge foam modified under mild conditions to produce rechargeable antibacterial substrates with unique nano-coral structures, enabling both chemical and mechanical antibacterial actions.

Ignasius Radix Astadi Praptono Jati, Adrianus Rulianto Utomo, Erni Setijawaty et al.

Abstract The aims of this research are to investigate the effects of different concentrations of butterfly pea flower extract infusion as an active agent on the properties of durian fruit albedo and eggshell-based smart edible films. The butterfly pea flower was extracted using water with the ratios of 1:50 (T1), 1:100 (T2), 1:150 (T3), 1:200 (T4), 1:250 (T5), and 1:300 (T6) (w/v). The film was formulated using durian albedo, eggshell, sorbitol, and cornstarch, which was mixed with butterfly pea flower extract and mold using the casting method. The analysis performed included anthocyanin and phenolic content, antioxidant activity, tensile strength, elongation, water vapor transmission rate, scanning electron microscopy, Fourier transform infrared spectroscopy, and smart indicator examination using fresh milk model system. Different concentrations of butterfly pea extract affect the physicochemical properties of smart edible film. The increase in extract concentration increased anthocyanin and phenolic contents, which align with the increase in antioxidant activity. Meanwhile, the presence of bioactive compounds in the formulation reduced the tensile strength of the film and increased its elongation, as confirmed by SEM and FTIR results. Smart edible film can act as an indicator in the fresh milk model by changing color according to the change in pH due to milk spoilage.

Zhang　Donghai, Pan　Mingxu, Li　Xu, Xu　Yong, Xiong　Hao

The new process of EAF→VOD→LF+VD→ pouring 6 t electrode rod → vacuum consumable remelting （VAR） with lower smelting cost was adopted to produce 15-5PH stainless steel instead of the traditional VIM+VAR process， the causes of point defects were analyzed by scanning electron microscopy and ASPEX detection methods. The results show that calcium aluminate and aluminum spinite exist in the self-consuming electrode， the instability of vacuum consumable remelting process will draw the ingot crown and non-metallic float into the melting pool and remain in the consumable ingot， resulting in point defects after forging.Through process optimization and improvement， the VOD reduction slag is adjusted from 9 kg/t aluminum to 8 kg/t ferrosilicon and 5 kg/t aluminum， the composition of refining slag is adjusted from （mass fraction）CaO 50%-55%， SiO2 10%-15%， Al2O3 20%-25% to CaO 45%-50%， SiO2 5%-10%， Al2O3 33%-38%， vacuum consumable remelting speed is increased from 4.2 kg/min to 6 kg/min， and the melting drop time is increased from 0.23 s to 0.27 s， the cleanliness of consumable electrode has been greatly improved， the melting speed has been controlled steadily， the non-metal floating matter on the liquid surface of the molten pool has been removed， low and high magnification inspection of the finished material have met the standard requirements， and the inspection pass rate has been increased to more than 98%.