RGB Achromatic Metalens Doublet for Digital Imaging.

Chromatic aberration is a major challenge faced by metalenses. Current methods to achieve broadband achromatic operation in metalenses usually suffer from limited size, numerical aperture, and working bandwidth due to the finite group delay of meta-atoms, thus restricting the range of practical applications. Multiwavelength achromatic metalenses can overcome those limitations, making it possible to realize larger numerical aperture (NA) and sizes simultaneously. However, they usually require three layers, which increases their fabrication complexity, and have only been demonstrated in small sizes, with low numerical aperture and modest efficiencies. Here, we demonstrate a 1 mm diameter red-green-blue achromatic metalens doublet with a designed NA of 0.8 and successfully apply the metalens in a digital imaging system. This work shows the potential of the doublet metasurfaces, extending their applications to digital imaging systems such as digital projectors, virtual reality glasses, high resolution microscopies, etc.

High-frequency repetitive transcranial magnetic stimulation protects against cerebral ischemia/reperfusion injury in rats: Involving the mitigation of ferroptosis and inflammation.

BACKGROUND AND AIM: Repetitive transcranial magnetic stimulation (rTMS) has been found to attenuate cerebral ischemia/reperfusion (I/R) injury. However, its effects and mechanism of action have not yet been clarified. It has been reported that cerebral I/R injury is closely associated not only with ferroptosis but also with inflammation. Hence, the current study aimed to investigate whether high-frequency rTMS attenuates middle cerebral artery occlusion (MCAO)-induced cerebral I/R injury and further to elucidate the mediatory role of ferroptosis and inflammation. METHODS: The protective effects of rTMS on experimental cerebral I/R injury were investigated using transient MCAO model rats. Neurological scores and pathological changes of cerebral ischemic cortex were assessed to evaluate the effects of rTMS on cerebral I/R injury. The involvement of ferroptosis and that of inflammation were examined to investigate the mechanism underlying the effects of rTMS. RESULTS: High-frequency rTMS remarkably rescued the MCAO-induced neurological deficits and morphological damage. rTMS treatment also increased the mRNA and protein expression of glutathione-dependent peroxidase 4, decreased the mRNA and protein levels of acyl-CoA synthetase long-chain family member 4 and transferrin receptor in the cortex. Moreover, rTMS administration reduced the cerebrospinal fluid IL-1ß, IL-6, and TNF-α concentrations. CONCLUSION: These findings implicated that high-frequency rTMS alleviates MCAO-induced cerebral I/R injury, and the underlying mechanism could involve the inhibition of ferroptosis and inflammation. Our study identifies rTMS as a promising therapeutic agent for the treatment of cerebral I/R injury. Moreover, the mechanistic insights into ferroptosis and inflammation advance our understanding of it as a potential therapeutic target for diseases beyond cerebral ischemia stroke.

A review of methods for classification and recognition of ASD using fMRI data.

Autism spectrum disorder (ASD) is a severe neuropsychiatric brain disorder that affects people's social communication and daily routine. Considering the phenomenon of abnormal brain function in the early stage of ASD, functional magnetic resonance imaging (fMRI), an excellent technique that measures brain activity, provides effective data to study ASD. Therefore, based on fMRI data of ASD cases, this paper reviews the progress of machine learning methods and deep learning methods in ASD classification and recognition in the last three years and summarizes the different research results of fMRI data extracted from the Autism Brain Imaging Data Exchange (ABIDE). From the classification performance of classification and recognition of ASD by the two methods, comparing the important classification indicators such as accuracy, sensitivity and specificity, the current challenges and future development trends are reported, which can provide an essential reference for the early diagnosis of ASD cases.

[Effect of electroacupuncture at "Shuigou" (GV26) and "Baihui" (GV20) on autophagy of hippo-campal neurons in rats with cerebral ischemia-reperfusion injury].

OBJECTIVE: To explore the effect of electroacupuncture (EA) at "Shuigou"(GV6) and "Baihui"(GV20) on autophagy of hippocampal neurons in cerebral ischemia-reperfusion (I/R) injury rats. METHODS: Forty-eight healthy male SD rats were randomly divided into sham operation, model and EA groups, with 16 rats in each group. The rat model of cerebral I/R injury was established by occlusion of the middle cerebral artery (MCAO). Rats of the EA group received EA at GV26 and GV20 for 20 min, once daily for 5 days. The neurological function of rats in each group was evaluated by Longa neurological function score. The cerebral infarction volume was measured by TTC staining. The levels of IL-6, IL-18 and TNF-α in cerebrospinal fluid were detected by ELISA. Real-time PCR and Western blot were respectively used to detect the expressions of autophagy-related proteins AMPK, Beclin-1, VPS34 and LC3B. RESULTS: Compared with the sham operation group, neurological function scores of rats in the model group were significantly increased (P<0.01); the volume of cerebral infarction was significantly increased (P<0.01); the contents of IL-6, IL-18 and TNF-α in cerebrospinal fluid were increased (P<0.01, P<0.05); the mRNA expression levels of AMPK, Beclin-1, VPS34 and LC3B were significantly increased (P<0.01); the protein expressions of AMPK, Beclin-1, VPS34 and the ratio of LC3B-Ⅱ/LC3B-Ⅰ were increased (P<0.01, P<0.05). After intervention and in comparison with the model group, the neurological function scores were decreased (P<0.05); the cerebral infarct volume were decreased (P<0.05); the contents of IL-6, IL-18 and TNF-α in cerebrospinal fluid were decreased (P<0.05); the mRNA expressions of AMPK, Beclin-1, VPS34 and LC3B were significantly decreased (P<0.01); the protein expressions of AMPK, Beclin-1, VPS34 and the ratio of LC3B-Ⅱ/LC3B-Ⅰ were decreased (P<0.05, P<0.01). CONCLUSION: EA can improve the neurological function and alleviate the degree of nerve injury in rats with cerebral I/R injury, which may be related to inhibiting the autophagy level of hippocampal neurons.

A follow-up study of 69 discharged SARS patients.

Sixty-nine patients with severe acute respiratory syndrome (SARS) discharged from Guangdong Provincial TCM Hospital were followed up from January to April 2003 during which the patients were asked to fill the questionnaire form and at the same time received blood routine examination, hepatic, renal, pulmonary and immune function tests, and spiral computerized tomography (CT) of the chest, color B-ultrasonography of the heart with the collected data treated by descriptive analysis and deductive analysis. The results showed that in the 69 followed-up patients, impairment of the hepatic function was found in 5 cases, hypoimmune state in 18, impediment of ventilation in the distal air passages with normal major air passages in 15, increased residual volume in 40, mild disturbance of pulmonary diffusion function in 14, incomplete absorption of inflammatory exudates, focal or multiple interstitial lesions, pulmonary interstitial fibrosis and pleural adhesion in 24; increased resistance or mild systolic hypertension in the pulmonary circulation, and segmental ischemia of the left myocardium in 34; and decreased visual acuity in 2. According to TCM differentiation 24 cases belonged to the type of deficiency of both qi and yin, 8 deficiency of both the heart and spleen, 37 depression of the liver and deficiency of the spleen, 18 intermingling with damp-heat, and 7 intermingling with stagnant blood. Some patients still had psychological problems. The study indicates that though clinically cured and discharged from hospital, some SARS patients have functional impairment of the heart, lung and liver, hypoimmune state as well as psychological problems, and need to be treated accordingly for a complete recovery. A rationale for suggested TCM treatment is expounded.