Unveiling the Dynamic Electrocatalytic Activity of Online Synthesized Bimetallic Nanocatalysts via Electrochemiluminescence Microscopy.

Effective bimetallic nanoelectrocatalysis demands precise control of composition, structure, and understanding catalytic mechanisms. To address these challenges, we employ a two-in-one approach, integrating online synthesis with real-time imaging of bimetallic Au@Metal core-shell nanoparticles (Au@M NPs) via electrochemiluminescence microscopy (ECLM). Within 120 s, online electrodeposition and in situ catalytic activity screening alternate. ECLM captures transient faradaic processes during potential switches, visualizes electrochemical processes in real-time, and tracks catalytic activity dynamics at the single-particle level. Analysis using ECL photon flux density eliminates size effects and yields quantitative electrocatalytic activity results. Notably, a nonlinear activity trend corresponding to the shell metal to Au surface atomic ratio is discerned, quantifying the optimal surface component ratio of Au@M NPs. This approach offers a comprehensive understanding of catalytic behavior during the deposition process with high spatiotemporal resolution, which is crucial for tailoring efficient bimetallic nanocatalysts for diverse applications.

Cascade Reaction Regulated Electrochemiluminescence via Dual-Atomic-Site Catalysts.

Single-atom catalysts (SACs), a novel kind of electrocatalysts with full metal utilization, have been developed as unique signal amplifiers in several sensing platforms. Herein, based on theoretical prediction of the oxygen reduction reaction (ORR) mechanism on different atom sites, we constructed dual-atomic-site catalysts (DACs), Fe/Mn-N-C, to catalyze luminol-dissolved oxygen electrochemiluminescence (ECL). Computational simulation indicated that the weak adsorption of OH* on a single Fe site was overcome by introducing Mn as the secondary metallic active site, resulting in a synergic dual-site cascade mechanism. The superior catalytic activity of Fe/Mn-N-C DACs for the ORR was proven by the highly efficient cathodic luminol ECL, surpassing the performance of single-site catalysts (SACs), Fe-N-C and Mn-N-C. Furthermore, the ECL system, enhanced by a cascade reaction, exhibited remarkable sensitivity to ascorbic acid, with a detection limit of 0.02 nM. This research opens up opportunities for enhancing both the ECL efficiency and sensing performance by employing a rational atomic-scale design for DACs.

Photoinduced Electrogenerated Chemiluminescence Imaging of Plasmonic Photoelectrochemistry at Single Nanocatalysts.

In this study, we proposed a novel imaging technique, photoinduced electrogenerated chemiluminescence microscopy (PECLM), to monitor redox reactions driven by hot carriers on single gold nanoparticles (AuNPs) on TiO2. Under laser irradiation, plasmon-generated hot carriers were separated by an electric field, leaving hot holes on the surface of AuNPs to drive ECL reactions. PECL intensity was highly sensitive to the number of hot carriers. Through quantitative image analysis, we found that PECL density on individual AuNPs decreased significantly with an increase in particle diameter, indicating that particle size has a significant impact on photoelectrochemical conversion efficiency. For the first time, we verified the feasibility of PECLM in mapping the catalytic activity of single photocatalysts. PECLM opens a new prospect for the in situ imaging of photocatalysis in a high-throughput way, which not only facilitates the optimization of plasmonic photocatalysts but also contributes to the dynamic study of photocatalytic processes on micro/nanointerfaces.

The enhanced longevity and liver targetability of Paclitaxel by hybrid liposomes encapsulating Paclitaxel-conjugated gold nanoparticles.

Organic and inorganic drug delivery systems both demonstrate their own advantages and challenges in practical applications. Combining these two drug delivery strategies in one system is expected to solve their current issues and achieve desirable functions. In this paper, gold nanoparticles (GNPs) and liposomes have been chosen as the model systems to construct a hybrid system and investigate its performance for the tumor therapy of Paclitaxel (PTX). The thiol-terminated polyethylene glycol (PEG400)-PTX derivative has been covalently modified on the surface of GNPs, followed by the encapsulation of PTX-conjugated GNPs (PTX-PEG400@GNPs) in liposomes. The hybrid liposomes solve the solubility and stability problems of gold conjugates and show high drug loading capacity. In vitro PTX release from the hybrid system maintains the similar sustained behavior demonstrated in its conjugates. Under the protection of a biocompatible liposome shell, encapsulated PTX shows enhanced circulation longevity and liver targetability compared to Taxol(®) and PTX-PEG400@GNPs suspension in the pharmacokinetic and biodistribution studies. These indicate that encapsulating drug-conjugated inorganic nanoparticles inside organic carriers maintains the superiority of both vehicles and improves the performance of hybrid systems. Although these attributes of hybrid liposomes lead to a better therapeutic capacity in a murine liver cancer model than that of the comparison groups, it shows no significant difference from Taxol(®) and conjugate suspension. This result could be due to the delayed and sustained drug release from the system. However, it indicates the promising potential for these hybrid liposomes will allow further construction of a compound preparation with improved performance that is based on their enhanced longevity and liver targetability of Paclitaxel.

Glutathione-mediated drug release from Tiopronin-conjugated gold nanoparticles for acute liver injury therapy.

Tiopronin-conjugated gold nanoparticles (TPN@GNPs), with glutathione (GSH)-responsive drug release property, were developed for acute liver injury therapy. The TPN@GNPs were prepared using a one-pot synthesis method and characterized by UV-vis and transmission electronic microscopy methods. The TPN@GNPs displayed typical surface plasmon resonance of nanogold with a narrow size distribution (ca. 2 nm). The in vitro drug release profiles of the conjugates indicated that TPN@GNPs were able to release TPN in a sustained fashion for 4 h at a simulated intracellular level of GSH. pH values or ionic strengths of the release media had no obvious influence on TPN release from the surface of nanoparticles. The pharmacokinetic studies in rats showed that the TPN@GNPs had longer MRT (7.71 h) than TPN (3.96 h), indicating sustained release pattern of TPN@GNPs in vivo. The sustained release of TPN at the relative high GSH concentration could ameliorate the instability of TPN and enable the drug release in the target cells. Although the IC50 value of TPN@GNPs with TPN/AuCl4(-) of 3:1 (mol/mol) showed slight increase in comparison with that of the free TPN in HepG2 cells (1.26±1.07 vs. 1.73±1.16 mg/mL), the TPN@GNPs displayed better effects over TPN in the treatment of acute liver injury in vivo. In a liver injury mice model induced by CCl4, the histological analysis showed both the TPN@GNPs and free TPN group could repair the liver injury. In addition, the biochemical parameters showed TPN@GNPs could reduced the aminotransferase to a lower level compared with TPN, which might be due to the sustained drug release and passive liver targeting properties of TPN@GNPs. It demonstrated that gold nanoparticle-based drug delivery system allowed smart functions and superior properties by taking advantages of the unique small size effects and surface chemical properties.

Langerhans cell sarcoma: a case report and literature review / 中华血液学杂志

<p><b>OBJECTIVE</b>To explorer the clinical features, diagnosis and therapy of Langerhans cell sarcoma (LCS).</p><p><b>METHODS</b>The clinical data of a case of LCS originated from cervical lymph nodes was analyzed. The pathological biopsy was studied by cell morphology, immunohistochemistry and electron microscopy, and the related literature was reviewed.</p><p><b>RESULTS</b>The giant tumor cells were characterized by markedly malignant proliferation, irregular nuclei and obviously chromatin abnormality, the positive S-100, CD1a and Langerin (CD207) tumor cells were revealed by immunohistochemistry, and Birbeck granules could be found by electron microscopy. All of them supported the diagnosis of LCS. The patient's condition progressed rapidly and died of multiple organ failure in a short time.</p><p><b>CONCLUSION</b>LCS is an extremely rare neoplastic proliferation of Langerhans cells with overtly malignant cytologic features and spreads aggressively. The diagnosis of LCS mainly relies on pathological cell morphology, immunohistochemistry and electron microscopy if necessary. The treatment includes chemotherapy, surgery and radiotherapy, etc, but lack of generally accepted optimal treatment regimen currently. In short, LCS has intensive invasiveness and poor prognosis.</p>

Clinicopathologic analysis of intestinal follicular lymphoma first presenting with gastrointestinal symptoms / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinical features, endoscopic findings, pathologic diagnosis and treatment options of intestinal follicular lymphoma first presenting with gastrointestinal symptoms.</p><p><b>METHODS</b>The clinical features, pathologic findings and follow-up data were retrospectively studied in 9 cases of intestinal follicular lymphoma. Immunohistochemical study for CD3, CD5, CD20, CD21, Ki-67, bcl-2, bcl-6, CD10 and cyclin D1 was carried out.</p><p><b>RESULTS</b>Seven of the 9 patients were females and two were males. The age of patients ranged from 5 to 60 years (mean = 44 years). The clinical manifestations included abdominal pain (5 cases), blood in stool (3 cases) and abdominal distension (1 case). The commonest site of involvement was ileocecal region (6/9). Endoscopic examination had been carried out in 6 patients and all showed the presence of multiple polyps. Five cases had undergone endoscopic biopsy. Histologic examination of the endoscopic biopsies showed lymphoma cells located mainly in mucosal layer, forming vague nodules with ill-defined boundaries. Plasma cells and eosinophils were not conspicuous. Immunohistochemically, the tumor cells in all cases diffusely expressed CD20, CD10 and bcl-2. The staining for CD3, CD5 and cyclin D1 was negative. Lymphoid cells with weak CD10-positivity were identified in the interfollicular regions. Four cases were treated with surgical resection and chemotherapy. The other 3 cases received chemotherapy only and the remaining cases were treated conservatively. All of them were still alive on follow up.</p><p><b>CONCLUSIONS</b>Primary intestinal follicular lymphoma affects predominantly elderly patients and has a female predilection. The commonest site of involvement is ileocecal region. Endoscopic examination shows polypoid changes. The disease often runs a relatively indolent clinical course. The prognosis is better than that of primary nodal follicular lymphoma.</p>

Loss of pan-T cell antigens CD2, CD3, CD5 and CD7 in Kikuchi's disease / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the possible loss of pan-T cell antigens CD2, CD3, CD5 and CD7 in Kikuchi's disease and to evaluate the role of T cell antigen loss in distinguishing benign from malignant T-cell lymphoid lesions.</p><p><b>METHODS</b>Formalin-fixed and paraffin-embedded tissues of 33 cases of Kikuchi's disease and 15 cases of reactive lymphoid hyperplasia were studied by EliVision immunohistochemical staining for CD2, CD3, CD5 and CD7.</p><p><b>RESULTS</b>Twenty-four of the 33 (72.7%) cases of Kikuchi's disease lost one or more of the pan-T cell antigens, including the loss of CD5 only (13 cases), CD7 only (1 case), CD2 only (1 case), CD2 and CD7 (2 cases), CD5 and CD7 (4 cases), CD2 and CD5 (2 cases), and CD2, CD7 and CD5 (1 case). Amongst these cases, the commonest antigen loss was CD5 (20 cases, 60.6%), followed by CD7 (8 cases, 24.2%) and CD2 (6 cases, 18.2%). Compared with the xanthomatous subtype of Kikuchi's disease, the loss of antigens was more commonly seen in the proliferative and necrotizing subtypes. Analysis of follow-up data showed that the loss of antigens in Kikuchi's disease was not significantly associated with the prognosis. In reactive lymphoid hyperplasia, the expression of CD2, CD3, CD5 and CD7 was seen in all cases with similar intensity, with no obvious pan-T cell antigen loss.</p><p><b>CONCLUSION</b>Loss of one or more pan-T cell antigens in Kikuchi's disease is demonstrated in present study, suggesting that the immunophenotypic pattern is not unique in T cell lymphoma.</p>

Clinicopathologic features of systemic EBV-positive T/NK-cell lymphoproliferative disease in adults / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features, immunophenotype, clonality and Epstein-Barr virus (EBV) status of systemic EBV-positive T/NK-cell lymphoproliferative disease in adults (ASEBV(+)T/NK-LPD).</p><p><b>METHODS</b>Twenty cases of ASEBV(+)T/NK-LPD were analyzed retrospectively with histopathologic review, immunohistochemistry and in-situ hybridization for EBV-encoded RNA (EBER). The follow-up data were collected.</p><p><b>RESULTS</b>There were altogether 15 males and 5 females. The median age of the patients was 34 years. The average duration from onset of symptoms to diagnosis was 8.7 months. Fever (18/20), hepatosplenomegaly (18/20) and lymphadenopathy (17/20) were the main clinical manifestations. Eleven of the 17 patients died during follow-up, with a mean survival of 2.9 months. Histologically, there was obvious expansion of T zone of the involved lymph nodes, associated with diminished lymphoid follicles. The interfollicular areas were widened and infiltrated by small to median-sized lymphoid cells which showed only mild atypia. Scattered large lymphoid cells were not uncommon. The nodal capsule was thickened in 6 cases. Focal necrosis was seen in 9 cases. Sinus histiocytic proliferation with erythrophagocytosis was observed in 3 cases. In addition, there were mild atypical lymphoid cells infiltrate into the liver, spleen, intestinal mucosa and bone marrow. Immunohistochemical study and in-situ hybridization showed that the EBER-positive cells were of T-cell lineage, with CD3 expression. They were also positive for cytotoxic molecules (granzyme B or TIA-1). Only 1 case was CD56 positive. A predominance of CD8-positive cells was demonstrated in 8 of the 14 cases studied, while CD4-positive cells predominated in the remaining 5 cases. One case showed similar proportion of CD8 and CD4-positive cells. The number of EBER-positive cells ranged from 30 to more than 300 per high-power fields. These EBER-positive cells were of small to large size and located mainly in the expanded T zone and occasionally in the germinal centers. Three of the 7 cases exhibited clonal rearrangement of T-cell receptor gamma gene, while the other 4 cases exhibited polyclonal rearrangement of T-cell receptor gamma gene.</p><p><b>CONCLUSIONS</b>ASEBV(+)T/NK-LPD is a systemic disease with a subacute or chronic clinical course. Most patients suffer from relapsing fever, lymphadenopathy and hepatosplenomegaly. The disease is characterized by proliferation of EBV-infected cytotoxic T cells. The T zone of the involved lymph nodes shows expansion by mildly atypical lymphoid cells. The disease is associated with poor clinical outcome and can be life-threatening. The patients often die of multiorgan failure and bleeding.</p>

Intralymphatic accumulation of lymphocytes mimicking intravascular lymphomatosis / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the significance and differential diagnosis of intralymphatic accumulation of lymphocytes.</p><p><b>METHODS</b>The clinical and pathologic features of 4 cases of intralymphatic accumulation of lymphocytes were reviewed retrospectively. Immunohistochemical study was carried out and follow-up data were analyzed.</p><p><b>RESULTS</b>The sites of involvement included tonsil (2 cases), pharynx (1 case) and appendix (1 case). The duration of disease ranged from 1 week to 3 months. Follow up of the patients (from 3 to 84 months) showed no evidence of disease recurrence. Gross examination of the tissues (except in the case of appendiceal involvement) showed polypoid changes. Histologically, the lymphatic channels were filled up with small lymphocytes and associated with fibrosis in the vicinity. Immunohistochemical study revealed a T-cell phenotype of the intralymphatic lymphoid cells.</p><p><b>CONCLUSIONS</b>The accumulation of lymphocytes in lymphatic channels is associated with a benign clinical course. This phenomenon may be due to retention of lymphocytes secondary to the perilymphatic chronic inflammation and fibrosis. Although the lesion simulates intravascular lymphomatosis morphologically and shows a uniform T-cell phenotype, the lymphoid cells lack obvious cellular pleomorphism and mitotic activity. The solitary nature of the lesion, when coupled with the indolent clinical behavior, is also helpful in the differential diagnosis.</p>

[Effects of simulated weightlessness on rats mandible, lumbar vertebra and femur].

OBJECTIVE: To observe the effect of weightlessness simulation on rats mandible, lumbar vertebra and femur. METHOD: Twenty five Wistar rats were randomly arranged into control group (n=10) and tail-suspension group (n=15 rats). The experiment lasted for 28 d. Then the mandible, lumbar vertebra and femur were excised and the histological structure of condylar process of mandible, molar and premolar area of mandible body, first lumbar, head, middle segment and condyle of femur were examined. RESULT: After tail-suspension there was no distinct change in bone density and bone mass of condylar process. But the degree of interlacement of trabecular bone increased. The bone substance of mandible was very dense in both control and experimental groups. There was no stimulated difference of bone structure and bone mass between the two groups. There was no marked change in the thickness of periodontal membrane. The bone lamella in premolar area of experimental group arranged regularly. And its maturity was higher than that in molar area. The line of bone hyperplasia in molar area of experimental group arranged disorderly and irregularly, which means that much bone remodeling occurred. The component of trabecular bone decreased in femur and lumbar vertebra and the thickness was uneven. The interlacement and connection among trabecular bones was poor. CONCLUSION: Four weeks of stimulated weightlessness can lead to osteoporosis in acantha and femur [correction of feurar] but has no distinct effect on mandible.