Quantitative detection of high-order Poincaré sphere beams and their polarization evolution.

The high-order Poincaré sphere (PS) introduces a mapping whereby any vector beams with spatially homogeneous ellipticity are represented by a specific point on the surface of the sphere. We propose the quantitative detection of high-order PS beams by introducing three sets of nonuniform polarization bases in the high-order Stokes parameters. Overall polarization detection is realized by directly separating and measuring the respective intensity of different nonuniform polarization bases based on S-plate. The polarization evolution of the PS beams on the high-order PS and between the conventional and the high-order PS are achieved by S-plate. The results provide new insights for the generation, evolution and detection of arbitrary beams on the high-order PS.

Cascaded stimulated Brillouin scattering erbium-doped fiber laser generating orbital angular momentum beams at tunable wavelengths.

We experimentally demonstrate a method to obtain central wavelength tunable orbital angular momentum beams with switchable topological charges (+1 or -1) in a stimulated Brillouin scattering erbium-doped fiber laser. Multiwavelength operation is achieved through cascaded stimulated Brillouin scattering in a single-mode fiber with a length of 6 km initiated by an external Brillouin pump. High-efficiency mode conversion between the fundamental mode and the orbital angular momentum modes is realized through a broadband two-mode long-period fiber grating. High-purity orbital angular momentum beams with up to 10 stable wavelength channels with a tuning range of 35 nm are achieved, which is the highest number of operating wavelengths and tuning range in an all-fiber laser for orbital angular momentum beam emission to the best of our knowledge. Both the operational central wavelength and number of operating wavelengths can be tuned by adjusting the primary pump power and the center wavelength of the tunable bandpass filter in conjunction with changing the Brillouin pump wavelength.

The Therapeutic Potential of Melatonin in Alzheimer's Disease: A Comprehensive Review.

Alzheimer's Disease (AD) is the most common cause of dementia, afflicting over 5 million people in the United States. There remains a lack of effective disease-- modifying treatments for AD beyond a few approved drugs that provide temporary symptomatic relief. Melatonin is an endogenous hormone mainly produced by the pineal gland that regulates circadian rhythms and possesses antioxidant and anti-inflammatory properties. An expansive body of research over the past few decades has investigated melatonin as a promising therapeutic agent for AD based on its ability to target multiple pathophysiological processes implicated in AD progression. In this comprehensive review, we summarize extensive evidence from cellular and animal models that has uncovered the diverse mechanisms underpinning melatonin's neuroprotective efficacy against AD pathology. We also synthesize clinical studies examining melatonin's effects on AD progression and symptoms. Additionally, we discuss how melatonin's multimodal mechanisms, favorable safety profile, and ability to synergize with conventional therapies heighten its potential as an effective therapeutic strategy for AD. Rigorously designed clinical trials incorporating physiological biomarkers are warranted to definitively establish melatonin's disease-modifying effects. Nevertheless, the considerable preclinical data support further exploration of melatonin as a therapeutic agent for AD.

Effect of bone cement distribution on adjacent disc degeneration after vertebral augmentation for osteoporotic vertebral compression fractures in aging patients.

Background: The influence of vertebral augmentation on adjacent intervertebral discs remains controversial. The purpose of this study is to evaluate the effect of bone cement distribution on adjacent disc degeneration after vertebral augmentation for osteoporotic vertebral compression fractures (OVCFs). Methods: Patients with single level OVCF and upper endplate injury who underwent vertebral augmentation were enrolled. The patients were divided into four groups: Group A: bone cement contacted both the cranial and the distal endplates; Group B: bone cement only contacted the cranial endplate; Group C: bone cement only contacted the distal endplate; and Group D: bone cement contacted neither the cranial nor the distal endplates. The cranial discs of the fractured vertebrae were defined as adjacent discs and the upper discs proximally to the adjacent discs were defined as control discs. Degenerative disc change (DDC) was defined as a deteriorated postoperative Pfirrmann score compared with the preoperative score on MR images. The number of DDC cases and the disc heights were analyzed among the groups. Results: A total of 184 patients with an average follow-up time of 28.6 months were included. The number of DDC cases in the adjacent discs was significantly higher than in the control discs in groups A (p < 0.001), B (p = 0.002), and D (p = 0.028), whereas the difference in group C was not statistically significant (p = 0.237). The incidence of adjacent disc degeneration was significantly higher in group A than that in group C (p = 0.06). The adjacent disc heights decreased significantly in groups A, B, and D (p < 0.001, p < 0.001, and p = 0.012, respectively), but did not decrease significantly in group C (p = 0.079). However, no statistical differences were detected among the four groups with respect to the preoperative adjacent disc height, follow-up adjacent disc height, preoperative control disc height, or follow-up control disc height. Conclusion: Bone cement distribution influences adjacent disc degeneration after vertebral augmentation in OVCFs. Cement distribution proximal to the injured endplate can accelerate adjacent disc degeneration, and cement in contact with both the cranial and distal endplates can induce a higher incidence of adjacent disc degeneration.

The Molecular Mechanisms Study of Engeletin Suppresses RANKL-Induced Osteoclastogenesis and Inhibits Ovariectomized Murine Model Bone Loss.

Objective: Osteoclastogenesis, the process of osteoclast differentiation, plays a critical role in bone homeostasis. Overexpression of osteoclastogenesis can lead to pathological conditions, such as osteoporosis and osteolysis. This study aims to investigate the role of Engelitin in the process of RAW264.7 cell differentiation into osteoclasts induced by RANKL, as well as in a mouse model of bone loss following ovariectomy. Methods: We used RANKL-stimulated RAW264.7 cells as an in vitro osteoclast differentiation model. The effects of Eng on morphological changes during osteoclast differentiation were evaluated using TRAP and F-actin staining. The effects of Eng on the molecular level of osteoclast differentiation were evaluated using Western blot and q-PCR. The level of reactive oxygen species was evaluated using the DCFH-DA staining method. We then used ovariectomized mice as a bone loss animal model. The effects of Eng on changes in bone loss in vivo were evaluated using micro-CT and histological analysis staining. Results: In the in vitro experiments, Eng exhibited dose-dependent inhibition of osteoclast formation and F-actin formation. At the molecular level, Eng dose-dependently suppressed the expression of specific RNAs (NFATc1, c-Fos, TRAP, Cathepsin K, MMP-9) involved in osteoclast differentiation, and inhibited the phosphorylation of proteins such as IκBα, P65, ERK, JNK, and P38. Additionally, Eng dose-dependently suppressed ROS levels and promoted the expression of antioxidant enzymes such as Nrf2, HO-1, and NQO1. In the in vivo experiments, Eng improved bone loss in ovariectomized mice. Conclusion: Our study found that Eng inhibited RANKL-induced osteoclast differentiation through multiple signaling pathways, including MAPKs, NF-κB, and ROS aggregation. Furthermore, Eng improved bone loss in ovariectomized mice.

[Study on the regulatory mechanism of electroacupuncture based on thyroid pathway for mammary gland hyperplasia rats].

OBJECTIVE: To study the regulating effect of thyroid pathway on electroacupuncture (EA) for mammary gland hyperplasia (MGH) so as to provide new research ideas for the mechanism of EA for MGH and to provide the evidence for clinical application. METHODS: Sixty adult female SD rats were randomly divided into a blank group, a model group, an EA group, an EA with thyroidectomy group, an EA with sham operation group, 12 rats in each one. Except the blank group, the MGH model was established. Thyroid ablation was performed in the EA with thyroidectomy group, and sham operation was used in the EA with sham operation group, exposing thyroid without excision, 1 day after model establishment. EA was applied in the EA, the EA with thyroidectomy, and the EA with sham operation groups on the 4th day after model establishment, and not used in the other groups, but catching, routine disinfection and fixation were all the same as the above groups. The acupoints in the group A were bilateral "Tianzong" (SI 11), "Ganshu" (BL 18) and "Zusanli" (ST 36); and those in the group B were bilateral "Wuyi" (ST 15), "Hegu" (LI 4) and "Danzhong" (CV 17). The two groups of points were alternately used. EA, continuous wave, 2 Hz and 1 mA, was connected at "Tianzong" (SI 11) and "Ganshu" (BL 18), "Wuyi" (ST 15) and "Hegu" (LI 4) at the same side, 2 pairs EA a time, 20 min a time, once a day. All the intervention was given for 4 courses, 5 times as 1 course with 2 days between courses. After intervention, the height and diameter of the rat papilla were measured. Estrogen (E2) and progestational hormone (P) in the serum were detected by enzyme linked immunosorbent assay (ELISA), and the contents and protein expression of estrogen receptor α (ERα) and progesterone receptor (PR) in the mammary glands were detected by immunofluorescence and Western-blot. RESULTS: (1) The height and diameter of papilla in the model group increased compared with those in the blank group (both P<0.01). The height and diameter of papilla in the EA, EA with sham operation groups reduced compared with those in the model group (all P<0.01). Those in the EA with thyroidectomy group were lower than those in the model group, without statistical significance (both P>0.05). (2) Compared with the blank group, E2 increased and P decreased in the model group (both P<0.01). Compared with the model group, E2 decreased and P increased in the EA and EA with sham operation groups (all P<0.01). The contents of E2 and P had no statistical significance between the model and the EA with thyroidectomy groups (both P>0.05). (3) Compared with the blank group, the ERα content and protein expression increased and the PR content and protein expression decreased in the model group (all P<0.01). Compared with the model group, the ERα content and protein expression decreased and the PR content and protein expression increased in the EA and EA with sham operation groups (all P<0.01). The ERα and PR content and protein expression had no statistical significance between the model and the EA with thyroidectomy groups (all P>0.05). CONCLUSION: The effect of EA for MGH may be closely related to the regulation of thyroid.