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BackgroundThe surgical microscope is used primarily for microsurgeries, which are more complicated than other surgical procedures and require delicate tasks for a long time. Therefore, during these surgical procedures, surgeons experience back and neck pain. To solve this problem, new technology, such as wearable displays, is required to help surgeons maintain comfortable postures and enjoy advanced functionality during microsurgery. ObjectiveThe objective of this study was to develop a surgical microscope system that would work with wearable devices. It would include a head-mounted display (HMD) that can offer 3D surgical images and allow a flexible and comfortable posture instead of fixed eyepieces of surgical microscope and can also provide peripheral visual field with its optical see-through function. MethodsWe designed and fabricated a surgical microscope system that incorporates a see-through type 3D HMD, and we developed an image processing software to provide better image quality. The usability of the proposed system was confirmed with preclinical examination. Seven ENT (ear, nose, and throat) surgical specialists and 8 residents performed a mock surgery—axillary lymph node dissection on a rat. They alternated between looking through the eyepieces of the surgical microscope and viewing a 3D HMD screen connected to the surgical microscope. We examined the success of the surgery and asked the specialists and residents to grade eye fatigue on a scale of 0 (none) to 6 (severe) and posture discomfort on a scale of 1 (none) to 5 (severe). Furthermore, a statistical comparison was performed using 2-tailed paired t test, and P=.00083 was considered significant. ResultsAlthough 3D HMD case showed a slightly better result regarding visual discomfort (P=.097), the average eye fatigue was not significantly different between eyepiece and 3D HMD cases (P=.79). However, the average posture discomfort, especially in neck and shoulder, was lower with 3D HMD display use than with eyepiece use (P=.00083). ConclusionsWe developed a see-through type 3D HMD–based surgical microscope system and showed through preclinical testing that the system could help reduce posture discomfort. The proposed system, with its advanced functions, could be a promising new technique for microsurgery.

Electrical conductivity is a pivotal biophysical factor for neural interfaces, though optimal values remain controversial due to challenges isolating this cue. To address this issue, conductive substrates made of carbon nanotubes and graphene oxide nanoribbons, exhibiting a spectrum of conductivities from 0.02 to 3.2 S m−1, while controlling other surface properties is designed. The focus is to ascertain whether varying conductivity in isolation has any discernable impact on neural lineage specification. Remarkably, neural‐tissue‐like low conductivity (0.02–0.1 S m−1) prompted neural stem/progenitor cells to exhibit a greater propensity toward neuronal lineage specification (neurons and oligodendrocytes, not astrocytes) compared to high supraphysiological conductivity (3.2 S m−1). High conductivity instigated the apoptotic process, characterized by increased apoptotic fraction and decreased neurogenic morphological features, primarily due to calcium overload. Conversely, cells exposed to physiological conductivity displayed epigenetic changes, specifically increased chromatin openness with H3acetylation (H3ac) and neurogenic‐transcription‐factor activation, along with a more balanced intracellular calcium response. The pharmacological inhibition of H3ac further supported the idea that such epigenetic changes might play a key role in driving neuronal specification in response to neural‐tissue‐like, not supraphysiological, conductive cues. These findings underscore the necessity of optimal conductivity when designing neural interfaces and scaffolds to stimulate neuronal differentiation and facilitate the repair process. [ABSTRACT FROM AUTHOR]

Background: Atrophic acne scarring is a common sequela of inflammatory acne, causing significant problems for affected patients. Although prolonged inflammation and subsequent aberrant tissue regeneration are considered the underlying pathogenesis, the role of epidermal stem cells, which are crucial to the regeneration of pilosebaceous units, remains unknown. Objectives: To examine the changes occurring in epidermal stem cells in atrophic acne scars. Methods: Changes in collagen, elastic fibre and human leukocyte antigen (HLA)‐DR expression were analysed in normal skin and inflammatory acne lesions at days 1, 3 and 7 after development. The expression of epidermal stem cell markers and proliferation markers was compared between normal skin and mature atrophic acne scar tissue. Results: In acne lesions, inflammation had invaded into pilosebaceous units over time. Their normal structure had been destructed and replaced with a reduced amount of collagen and elastic fibre. Expression of stem cell markers including CD34, p63, leucine‐rich repeat‐containing G protein‐coupled receptor (LGR)6 and LGR5, which are expressed in the interfollicular epidermis, isthmus and bulge of hair follicles, significantly decreased in atrophic acne scar tissue compared to normal skin. Epidermal proliferation was significantly reduced in scar tissue. Conclusions: These findings suggest that as inflammatory acne lesions progress, inflammation gradually infiltrates the pilosebaceous unit and affects the resident stem cells. This disruption impedes the normal regeneration of the interfollicular epidermis and adnexal structures, resulting in atrophic acne scars. [ABSTRACT FROM AUTHOR]

In recent years, there has been a surge in demand for and research focus on cell therapy, driven by the tissue-regenerative and disease-treating potentials of stem cells. Among the candidates, dental pulp stem cells (DPSCs) or human exfoliated deciduous teeth (SHED) have garnered significant attention due to their easy accessibility (non-invasive), multi-lineage differentiation capability (especially neurogenesis), and low immunogenicity. Utilizing these stem cells for clinical purposes requires careful culture techniques such as excluding animal-derived supplements. Human platelet lysate (hPL) has emerged as a safer alternative to fetal bovine serum (FBS) for cell culture. In our study, we assessed the impact of hPL as a growth factor supplement for culture medium, also conducting a characterization of SHED cultured in hPL-supplemented medium (hPL-SHED). The results showed that hPL has effects in enhancing cell proliferation and migration and increasing cell survivability in oxidative stress conditions induced by H2O2. The morphology of hPL-SHED exhibited reduced size and elongation, with a differentiation capacity comparable to or even exceeding that of SHED cultured in a medium supplemented with fetal bovine serum (FBS-SHED). Moreover, no evidence of chromosome abnormalities or tumor formation was detected. In conclusion, hPL-SHED emerges as a promising candidate for cell therapy, exhibiting considerable potential for clinical investigation. [ABSTRACT FROM AUTHOR]

Background/Objectives: This study aimed to investigate the influence of the root canal morphology and various treatment variables on the outcomes of root canal treatments (RCTs) in mandibular second molars, assessed through cone-beam computed tomography (CBCT) imaging. Methods: A total of 150 CBCT images were examined, comprising 100 cases of persistent endodontic infections and 50 of previously treated root canals with normal apices in the mandibular second molars. CBCT was utilized to evaluate the root canal configuration, the radiographic quality of coronal restorations and treated canal systems, and the presence of periapical lesions. Statistical analyses were performed to explore the correlations between these factors. Results: The presence of a C-shaped root canal configuration did not demonstrate a significant correlation with periapical lesions (p = 0.05). Factors influencing endodontic treatment outcomes included missing canals (p = 0.018), underfilling or overfilling (p = 0.045), and inadequate coronal restoration (p = 0.006). Missing a canal was identified as the variable most significantly associated with periapical lesions (OR = 3.103). Inhomogeneous root canal obturation was more commonly observed in C-shaped root canals (p < 0.001). Conclusions: Regardless of the root canal morphology of mandibular second molars, successful RCT depends on thorough disinfection to eliminate any untreated canals, precise three-dimensional filling of the canals at the correct working length, and a securely sealed coronal restoration to prevent leakage. [ABSTRACT FROM AUTHOR]

Background: Differences in clinical efficacy based on the fluence of fractional picosecond laser treatment for acne scars are unknown. Objective: To compare the efficacy and safety of low‐fluence versus high‐fluence fractional picosecond Nd:YAG 1064‐nm laser treatment in acne scar patients. Methods: In this 12‐week, investigator‐blinded, randomized, split‐face study, 25 patients with moderate‐to‐severe acne scars received three sessions of high‐fluence laser treatment (1.0 J/cm2) on one side of their face and low‐fluence (0.3 J/cm2) on the other side every 4 weeks. Patients were assessed using acne scar counts, the scar global assessment (SGA), and the ECCA scar grading scale every 4 weeks. The histological analysis compared the acne scars obtained before and 4 weeks after treatment. Results: At their last visit, 88.00% and 92.00% of the subjects achieved >30% reduction in scar counts on the low‐ and high‐fluence sides, respectively, without a significant difference between the two sides. On both sides, the scar counts, SGA, and ECCA score significantly improved 4 weeks after the last treatment. Although the high‐fluence side showed a greater reduction in scar counts (−66.73%) than the low‐fluence side (−62.13%), the two sides had no significant difference in the grading scores. The high‐fluence side showed significantly more severe pain and higher side‐effect scores immediately and 4 weeks after treatment. Histological analysis revealed a significantly increased collagen, elastin, and vimentin expression after treatment on the low‐fluence side. Conclusions: The low‐fluence setting demonstrated comparable efficacy and superior safety in treating acne scars compared with the high‐fluence setting. [ABSTRACT FROM AUTHOR]