Design and characterization of a variable-stiffness ankle-foot orthosis.

BACKGROUND: Ankle-foot orthoses (AFOs) are a type of assistive device that can improve the walking ability of individuals with neurological disorders. Adjusting stiffness is a common way to customize settings according to individuals' impairment. OBJECTIVE: This study aims to design a variable-stiffness AFO by stiffness module and characterize the AFO stiffness range to provide subject-specific settings for the users. METHODS: We modeled AFO using bending beams with varying fulcrum positions to adjust the stiffness. To characterize the stiffness range and profile, we used the superposition method to generate the theoretical model to analyze the AFO numerically. The intrinsic deformation of the bending beam in the AFO is considered a combination of 2 bending deformations to replicate actual bending conditions. The corresponding experiments in different fulcrum positions were performed to compare with and optimize the theoretical model. The curve fitting method was applied to tune the theoretical model by adding a fulcrum position-related coefficient. RESULTS: The AFO stiffness increased as the fulcrum moved to the proximal position. The maximum stiffness obtained was 1.77 Nm/° at a 6-cm fulcrum position, and the minimum stiffness was 0.82 Nm/° at a 0.5-cm fulcrum position with a 0.43-cm thick fiberglass beam. The corresponding theoretical model had maximum and minimum stiffness of 1.71 and 0.80 Nm/°, respectively. The theoretical model had a 4.08% difference compared with experimental values. CONCLUSIONS: The stiffness module can provide adjustable stiffness with the fulcrum position and different kinds of fiberglass bars, especially the thickness and material of the beam. The theoretical model with different fulcrum positions can be used to profile the real-time stiffness of the AFO in a dynamic motion and to determine the appropriate dimensions of the bending beam.

A universal metasurface antenna to manipulate all fundamental characteristics of electromagnetic waves.

Metasurfaces have promising potential to revolutionize a variety of photonic and electronic device technologies. However, metasurfaces that can simultaneously and independently control all electromagnetics (EM) waves' properties, including amplitude, phase, frequency, polarization, and momentum, with high integrability and programmability, are challenging and have not been successfully attempted. Here, we propose and demonstrate a microwave universal metasurface antenna (UMA) capable of dynamically, simultaneously, independently, and precisely manipulating all the constitutive properties of EM waves in a software-defined manner. Our UMA further facilitates the spatial- and time-varying wave properties, leading to more complicated waveform generation, beamforming, and direct information manipulations. In particular, the UMA can directly generate the modulated waveforms carrying digital information that can fundamentally simplify the architecture of information transmitter systems. The proposed UMA with unparalleled EM wave and information manipulation capabilities will spark a surge of applications from next-generation wireless systems, cognitive sensing, and imaging to quantum optics and quantum information science.

Wideband circular polarizer for a photoconductive antenna.

We report a thin-film circular polarizer consisting of three metal-grid layers to be used with a photoconductive antenna (PCA) to generate terahertz (THz) circularly polarized (CP) radiation. The polarizer has a high transmission with a measured 3 dB axial-ratio bandwidth of 54.7% from 0.57 to 1 THz. We further developed a generalized scattering matrix approach to provide insight into the underlying physical mechanism of the polarizer. We revealed that the Fabry-Pérot-like multi-reflection among gratings enables the high-efficiency polarization conversion. The successful realization of the CP PCA can find widespread application, such as THz circular dichroism spectroscopy, THz Mueller imaging, and ultrahigh-speed THz wireless communications.

A 6G meta-device for 3D varifocal.

The sixth-generation (6G) communication technology is being developed in full swing and is expected to be faster and better than the fifth generation. The precise information transfer directivity and the concentration of signal strength are the key topics of 6G technology. We report the synthetic phase design of rotary doublet Airy beam and triplet Gaussian beam varifocal meta-devices to fully control the terahertz beam's propagation direction and coverage area. The focusing spot can be delivered to arbitrary positions in a two-dimensional plane or a three-dimensional space. The highly concentrated signal can be delivered to a specific position, and the transmission direction can be adjusted freely to enable secure, flexible, and high-directivity 6G communication systems. This technology avoids the high costs associated with extensive use of active components. 6G communication systems, wireless power transfer, zoom imaging, and remote sensing will benefit from large-scale adoption of such a technology.

Podocalyxin-Like Protein 1 Regulates Pluripotency through the Cholesterol Biosynthesis Pathway.

Deciphering signaling mechanisms critical for the extended pluripotent stem cell (EPSC) state and primed pluripotency is necessary for understanding embryonic development. Here, a membrane protein, podocalyxin-like protein 1 (PODXL) as being essential for extended and primed pluripotency, is identified. Alteration of PODXL expression levels affects self-renewal, protein expression of c-MYC and telomerase, and induced pluripotent stem cell (iPSC) and EPSC colony formation. PODXL is the first membrane protein reported to regulate de novo cholesterol biosynthesis, and human pluripotent stem cells (hPSCs) are more sensitive to cholesterol depletion than fibroblasts. The addition of exogenous cholesterol fully restores PODXL knockdown-mediated loss of pluripotency. PODXL affects lipid raft dynamics via the regulation of cholesterol. PODXL recruits the RAC1/CDC42/actin network to regulate SREBP1 and SREBP2 maturation and lipid raft dynamics. Single-cell RNA sequencing reveals PODXL overexpression enhanced chimerism between human cells in mouse host embryos (hEPSCs 57%). Interestingly, in the human-mouse chimeras, laminin and collagen signaling-related pathways are dominant in PODXL overexpressing cells. It is concluded that cholesterol regulation via PODXL signaling is critical for ESC/EPSC.

Metasurface-based Fourier lens fed by compact plasmonic optical antennas for wide-angle beam steering.

A Fourier lens can perform the Fourier transform of an incident wavefront at the focal plane. This paper reports a metasurface-based Fourier lens fed by compact plasmonic optical antennas for wide-angle beam steering. The metasurface, composed of six elements with different configurations covering the 2π phase range, features a large field-of-view (FOV) of ±50°. A novel plasmonic optical antenna for broadside radiation is then designed as the feed source of the metasurface. The proposed antenna has ultra-compact size of 0.77λ × 1.4λ, and achieves a high directivity of 9.6 dB and radiation efficiency of over 80% at the wavelength of 1550 nm. Full-wave simulations are carried out to evaluate the performances of the designed metasurface-assisted beam steering device. The results show that this device can achieve a maximum directivity of 21.5 dB at broadside radiation. Compared to conventional Yagi-Uda antenna feed, a directivity enhancement of about 2.7 dB can be obtained, exhibiting a great superiority of the proposed feed antenna. In addition, a large beam steering range of ±50° can be achieved with an acceptable gain drop of 2.83 dB. With the advantages of wide beam steering range, good radiation characteristics, small footprint, and ease of integration, the proposed metasurface-assisted beam steering device would be a promising candidate for integrated photonic applications, including wireless optical communications, light detection and ranging, and augmented reality.

In Situ Measurements of Strain Evolution in Graphene/Boron Nitride Heterostructures Using a Non-Destructive Raman Spectroscopy Approach.

The mechanical properties of engineered van der Waals (vdW) 2D materials and heterostructures are critically important for their implementation into practical applications. Using a non-destructive Raman spectroscopy approach, this study investigates the strain evolution of single-layer graphene (SLGr) and few-layered boron nitride/graphene (FLBN/SLGr) heterostructures. The prepared 2D materials are synthesized via chemical vapor deposition (CVD) method and then transferred onto flexible polyethylene terephthalate (PET) substrates for subsequent strain measurements. For this study, a custom-built mechanical device-jig is designed and manufactured in-house to be used as an insert for the 3D piezoelectric stage of the Raman system. In situ investigation of the effects of applied strain in graphene detectable via Raman spectral data in characteristic bonds within SLGr and FLBN/SLGr heterostructures is carried out. The in situ strain evolution of the FLBN/SLGr heterostructures is obtained in the range of (0-0.5%) strain. It is found that, under the same strain, SLG exhibits a higher Raman shift in the 2D band as compared with FLBN/SLGr heterostructures. This research leads to a better understanding of strain dissipation in vertical 2D heterostacks, which could help improve the design and engineering of custom interfaces and, subsequently, control lattice structure and electronic properties. Moreover, this study can provide a new systematic approach for precise in situ strain assessment and measurements of other CVD-grown 2D materials and their heterostructures on a large scale for manufacturing a variety of future micro- and nano-scale devices on flexible substrates.

Blast-Related Traumatic Brain Injuries Secondary to Thermobaric Explosives: Implications for the War in Ukraine.

Blast-related traumatic brain injury (bTBI) is a significant cause of wartime morbidity and mortality. In recent decades, thermobaric explosives have emerged as particularly devastating weapons associated with bTBI. With recent documentation of the use of these weapons in the war in Ukraine, clinicians and laypersons alike could benefit from an improved understanding behind the dynamic interplay between explosive weaponry, its potential for bTBI, and the subsequent long-term consequences of these injuries. Therefore, we provide a general overview of the history and mechanism of action of thermobaric weapons and their potential to cause bTBI. In addition, we highlight the long-term cognitive and neuropsychiatric sequelae following bTBI and discuss diagnostic, therapeutic, and rehabilitation strategies, with the aim of helping to guide mitigation strategies and humanitarian relief in Ukraine. Thermobaric weapons produce a powerful blast wave capable of causing bTBIs, which can be further classified from primary to quaternary injuries. When modeling the hypothetical use of thermobaric weapons in Odessa, Ukraine, we estimate that the detonation of a salvo of thermobaric rockets has the potential to affect approximately 272 persons with bTBIs. In addition to the short-term damage, patients with bTBIs can present with long-term symptoms (e.g., post-traumatic stress disorder), which incur substantial financial costs and social consequences. Although these results are jarring, history has seen radical advancements in the understanding, diagnosis, and management of bTBI. Moving forward, a better understanding of the mechanism and long-term sequelae of bTBIs could help guide humanitarian relief to those affected by the war in Ukraine.

Development of a Chemical Cocktail That Rescues Mouse Brain Demyelination in a Cuprizone-Induced Model.

Oligodendrocytes are glial cells located in the central nervous system (CNS) that play essential roles in the transmission of nerve signals and in the neuroprotection of myelinated neurons. The dysfunction or loss of oligodendrocytes leads to demyelinating diseases such as multiple sclerosis (MS). To treat demyelinating diseases, the development of a therapy that promotes remyelination is required. In the present study, we established an in vitro method to convert human fibroblasts into induced oligodendrocyte-like cells (iOLCs) in 3 days. The induced cells displayed morphologies and molecular signatures similar to oligodendrocytes after treatment with valproic acid and exposure to the small molecules Y27632, SU9516, and forskolin (FSK). To pursue the development of a cell-free remyelination therapy in vivo, we used a cuprizone-induced demyelinated mouse model. The small molecules (Y27632, SU9516, and FSK) were directly injected into the demyelinated corpus callosum of the mouse brain. This combination of small molecules rescued the demyelination phenotype within two weeks as observed by light and electron microscopy. These results provide a foundation for exploring the development of a treatment for demyelinating diseases via regenerative medicine.

3D finite-element modeling of air-cell-based cushions and buttock tissues during prolonged sitting.

INTRODUCTION: Prolonged sitting can lead to serious health issues. Patients with spinal cord injuries may even develop pressure ulcers as stress accumulates on the ischial tuberosity. Air-cell-based (ACB) cushions have been shown to reduce tissue stress and help mitigate the effects of chronic sitting. Meanwhile, finite-element simulations have been implemented for different patient conditions. However, existing models are mostly two-dimensional with unrealistic simplifications. METHODS: A realistic three-dimensional multi-physics model with fewer artificial assumptions is presented. A commercial ACB cushion and an emulational buttock consisting of an actual hip bone and soft tissue (muscle, fat, and skin layers) were considered. Computational Fluid Dynamics and Transient Structural Analysis using ANSYS were utilized to simulate the ACB cushion during expansion and buttock tissue during sitting. RESULTS: Profile of airflow and pressure distributions caused by the airflow within the ACB cushion were computed when the air was pumped into the cells. Expansion of the ACB cushion was simulated, and an optimal inner pressure range (100-500 Pa) was determined. The human buttock sitting on the cushion was then simulated and visualized. CONCLUSIONS: The realistic three-dimensional model can accurately capture deformation and stress profiles pertinent to sitting on an ACB cushion. The model allows us to optimize the ACB cushions and operating conditions missing in previous studies. The model has also resolved several weaknesses in former models, such as the artificial air layers between air cells and unrealistically imposed internal pressure.

Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in 13 children / 中华儿科杂志

Objective: To analyze the clinical characteristics, treatment and prognosis of Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in children. Methods: A retrospective analysis was performed on the clinical features, laboratory tests, neuroelectrophysiological examination, imaging, treatment and outcomes of 13 patients with Hashimoto's encephalopathy presenting with isolated cerebellar ataxia, who were admitted to the Department of Pediatric Neurology of Guangzhou Women and Children's Medical Center from January 2016 to May 2021. Results: Among the 13 cases, 6 were males and 7 were females. The onset age was 2.6 (2.0,3.3) years, 9 children had precursor infection or vaccination before the first course of disease. All the 13 children had gait abnormalities or unsteady sitting, 10 had intentional tremor, 6 had dysarthria, 3 had body tremor, 2 had nystagmus, 3 had fatigue, 3 had hypotonia, 2 had vomiting and 1 had irritability. Thyroglobulin antibody (TgAb) was 500.0 (298.9,587.2) kU/L and thyroid peroxidase antibody (TPOAb) was 621.9 (449.6,869.4) kU/L in 13 cases. Autoantibodies were positive in 9 cases, and cerebrospinal fluid leukocytosis was seen in 4 cases. Regarding electroencephalography result, 4 cases had background slowing and 1 case had occasional sharp waves. Among the 3 patients who had relapses, 1 had cerebellar atrophy shown on cranial magnetic resonance imaging (MRI) during the recurrence. All the patients received intravenous immunoglobulin (IVIG) and intensive methylprednisolone therapy during the first onset, followed by the disappearance of the symptoms, 1 patient had repeated episodes which was decreased after immunosuppressive treatment with Rituximab.Followed up for 25.0 (22.5,33.3) months after the last episode, 12 achieved complete remission and 1 had a wide base gait. Conclusions: Trunk ataxia is the common symptom of Hashimoto's encephalopathy presenting with isolated cerebellar ataxia in children.Children with cerebellar ataxia should be tested for TgAb and TPOAb to detect Hashimoto's encephalopathy, avoiding missed diagnosis and treatment delays; IVIG and intensive steroid therapy is effective, and immunosuppressive therapy for patients with multiple relapses could reduce the recurrence.

Diagnosis of a child with mitochondrial myopathy and cerebellar atrophy with ataxia due to compound heterozygous variants of MSTO1 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child with myopathy and cerebellar atrophy with ataxia.@*METHODS@#Clinical examinations and laboratory testing were carried out for the patient. The proband and the parents' genomic DNA was extracted from peripheral blood samples and subjected to trio whole-exome sequencing. Candidate variant was validated by Sanger sequencing.@*RESULTS@#The 1-year-and-8-month-old boy manifested motor developmental delay, ataxia, hypomyotonia, increased serum creatine kinase. Cranial MRI showed cerebellar atrophy with progressive aggravation. Genetic testing revealed that the patient has harbored compound heterozygous variants of the MSTO1 gene, namely c.13delG (p.Ala5ProfsTer68) and c.971C>T (p.Thr324Ile), which were respectively inherited from his mother and father. The former was unreported previously and was predicted to be likely pathogenic, whilst the latter has been reported previously and was predicted to be of uncertain significance.@*CONCLUSION@#The compound heterozygous c.13delG (p.Ala5ProfsTer68) and c.971C>T (p.Thr324Ile) variants probably underlay the disease in the proband. Above finding has enriched the spectrum of MSTO1 gene variants underlying mitochondrial myopathy and cerebellar atrophy with ataxia.

Soft, Bistable Actuators for Reconfigurable 3D Electronics.

Existing strategies for reconfigurable three-dimensional (3D) electronics are greatly constrained by either the complicated driven mechanisms or harsh demands for conductive materials. Developing a simple and robust strategy for 3D electronics reconstruction and function extension remains a challenge. Here, we propose a solvent-driven bistable actuator, which acts as a substrate to reconstruct the combined 3D electronic device. Extraction of silicon oil from a hybrid poly(dimethylsiloxane) (PDMS) circle sheet buckles the dish to a bistable structure. The ultraviolet (UV)/ozone treatment on one surface of the PDMS structure introduces an oxidized layer, yielding a bilayered, solvent-driven bistable smart actuator. The snap-back stimulus to the oxidized layer differs from the snap-through stimulus. Experimental and numerical studies reveal the fundamental regulations for buckling configurations and the bistable behavior of the actuator. The prepared bistable actuator drives the bonded kirigami polyimide (PI) sheets to diverse 3D structures from the original bending configuration, reversibly. A frequency-reconfigurable electrically small monopole antenna is presented as a demonstration, which paves a way for the applications of this actuator in the field of reconfigurable 3D electronics.

Demonstration of a terahertz multi-spectral 3×3 Mueller matrix polarimetry system for 2D and 3D imaging.

Mueller matrix polarimetry (MMP) has been demonstrated and recognized as an effective approach to attaining imaging enhancement as well as revealing polarization properties of an imaged sample. Generally, a minimum of 16 combinations of intensity-only measurements involving both linear and circular polarizations are required to completely and accurately determine the 4 × 4 Mueller matrix (MM) and comprehensively describe the polarization properties of the sample. However, broadband circular polarizations (CP) are rather difficult to obtain for design and fabrication limitations in the terahertz region, which poses a challenge to the acquisition of the 4 × 4 MM. In this circumstance, the 3 × 3 MM degradation using only linear polarizations (LP) is preferred and sufficient for characterization of non-depolarizing samples. In this paper, a multi-spectral 3 × 3 MMP system based on the THz time-domain spectroscopy (THz-TDS) is established from 0.1 to 1 THz. The system demonstrated is capable of fulfilling the accurate determination of the 3 × 3 MM. The Mueller matrix polar decomposition (MMPD), modified to be compatible with the MM degradation, is employed to explore the fine details and properties of the sample. By signal post-processing techniques, the MM elements in the time domain are retrieved, and the time dimension reflecting the depth information facilitates the 3D reconstruction of the sample. This work provides a prototype for 3D imaging of biological samples at higher frequencies in the future.

Analysis of a family with inherited generalized epilepsy with febrile seizures plus caused by the KCNT2 mutation and literature review / 中华实用儿科临床杂志

Objective:To explore the clinical characteristics and treatment of a family with inherited generalized epilepsy with febrile seizures plus (GEFS + ) caused by the KCNT2 gene mutation and review the literature. Methods:Clinical data of a child with GEFS + and his family members who visited Department of Pediatric Neurology, Guangzhou Women and Children′s Medical Center in May 2019 were collected.DNA samples were collected from the peripheral blood of the proband, his parents, his elder brother, and his maternal grandparents, and genetic analysis and verification were performed using the next-generation sequencing technique.Using " KCNT2" as the key word, literature was retrieved from PubMed, China National Knowledge Infrastructure and Wanfang databases (up to August 2019). Results:The proband was a 3-year-old boy who was admitted to Guangzhou Women and Children′s Medical Center because of frequent epileptic seizures in the past 5 months.He presented with a binocular gaze and experienced 3 to 8 times of extremities myoclonic-spastic epileptic attacks every day.He had a history of 3 times of febrile seizures at the age of 2 years old.His seizures were refractory to Sodium valproate, Topiramate, Nitrazepam and Levetiracetam.His elder brother and mother had a history of childhood febrile seizures.Other members in the family had no history of convulsion.Ictal electroencephalogram showed general 1 Hz high voltage spike-slow waves.A heterozygous nonsense mutation of KCNT2 gene c. 574C>T(p.Q192X) that was never reported previously was detected in the proband, his brother, mother and maternal grandmother.Furthermore, no other family members carried the mutation at the c. 574 locus of the KCNT2 gene.No article in Chinese was found, and 2 articles in a language other than Chinese provided the complete data of 3 sporadic cases.Together with 4 cases in the family studied in this article, there were 7 cases and 4 mutation sites in KCNT2 gene.Of these mutations, there were 3 missense mutations and 1 nonsense mutation.Three sporadic patients presented with early infantile epileptic encephalopathy.The family of this study was characterized with febrile seizures and febrile seizures plus. Conclusions:A de novo mutation and phenotype of the KCNT2 gene is found in a family with GEFS + .It would expand the gene mutation spectrum and provide basis for family genetic counseling. KCNT2 mutation induced GEFS + is refractory to antiepileptic drugs.

Natural ingredients from Chinese materia medica for pulmonary hypertension / 中国天然药物

Pulmonary hypertension (PH) is a severe pathophysiological condition characterized by pulmonary artery remodeling and continuous increases in pulmonary artery pressure, which may eventually develop to right heart failure and death. Although newly discovered and incredible treatment strategies in recent years have improved the prognosis of PH, limited types of effective and economical drugs for PH still makes it as a life-threatening disease. Some drugs from Chinese materia medica (CMM) have been traditionally applied in the treatment of lung diseases. Accumulating evidence suggests active pharmaceutical ingredients (APIs) derived from those medicines brings promising future for the prevention and treatment of PH. In this review, we summarized the pharmacological effects of APIs derived from CMM which are potent in treating PH, so as to provide new thoughts for initial drug discovery and identification of potential therapeutic strategies in alternative medicine for PH.

Glycogen storage syndrome type 0 caused by GYS2 gene variation and phenotypic differences between two siblings / 中华医学遗传学杂志

OBJECTIVE@#To provide a basis for genetic counseling and clinical precision therapy by exploring the genetic etiology of a child with recurrent hypoglycemia convulsion accompanied by language retardation.@*METHODS@#Peripheral blood samples were obtained from the proband, his sister and his parents. Whole genomic DNA was extracted and analyzed by the whole exon gene sequencing and confirmed by Sanger sequencing.@*RESULTS@#The proband and his sister were found to carry compound heterozygous variants c.731T>A (p.M244L) and c.928G>A (p.G244S) of the GYS2 gene, which had not been reported in the past, the c.731T>A (p.M244L) site was derived from the maternal heterozygous mutation, while c.928G>A (p.G244S) site from the father heterozygous mutation.@*CONCLUSION@#The compound heterozygous variants c.731T>A (p.M244L) and c.928G>A (p.G244S) of the GYS2 gene were the genetic cause of glycogen storage syndrome type 0 in children, providing basis for family genetic counseling. When the patient had Hypoglycemia often accompanied with convulsions, which was easy to be misdiagnosed as seizures, and the antiepileptic treatment was ineffective. After genetic diagnosis, the seizure can be controlled by improving diet to maintain blood glucose stability.

miR-524-5p reduces the progression of the BRAF inhibitor-resistant melanoma.

BRAF inhibitors were approved for the treatment of BRAF-mutant melanoma. However, most patients acquire the resistance to BRAF inhibitors after several months of treatment. miR-524-5p is considered as a tumor suppressor in many cancers, including melanoma. In this study, we investigated the biological functions of miR-524-5p in melanoma with acquired resistance to BRAF inhibitor and evaluated the endogenous miR-524-5p expression as a biomarker for melanoma. The results showed that the expression of miR-524-5p was 0.481-fold lower in melanoma tissues (n = 117) than in nevus tissues (n = 40). Overexpression of miR-524-5p significantly reduced proliferative, anchorage-independent growth, migratory and invasive abilities of BRAF inhibitor-resistant melanoma cells. Moreover, the introduction of miR-524-5p led to a reduced development of BRAF inhibitor-resistant melanoma in vivo. Remarkably, the MAPK/ERK signaling pathway was decreased after treatment with miR-524-5p. Furthermore, next-generation sequencing analysis implied that the complement system, leukocyte extravasation, liver X receptor/retinoid-X-receptor activation, and cAMP-mediated signaling may be related to miR-524-5p-induced pathways in the resistant cells. The miR-524-5p level was higher on average in complete response and long-term partial response patients than in progressive disease and short-term partial response patients treated with BRAF inhibitors. Our results proposed that miR-524-5p could be considered as a target for treatment BRAF inhibitor-resistant melanoma and a prognostic marker in the response of patients to BRAF inhibitors for melanoma.

Selection of a malignant subpopulation from a colorectal cancer cell line.

Colorectal cancer (CRC) is a leading cause of cancer-associated mortality worldwide; therefore, there is an emerging need for novel experimental models that allow for the identification and validation of biomarkers for CRC-specific progression. In the present study, a repeated sphere-forming assay was used as a strategy to select a malignant subpopulation from a CRC cell line, namely HCT116. The assay was validated by confirming that canonical stemness markers were upregulated in the sphere state at every generation of the selection assay. The resulting subpopulation, after eight rounds of selection, exhibited increased sphere-forming capacity in vitro and increased tumorigenicity in vivo. Furthermore, dipeptidase 1 (DPEP1) was identified as the major differentially expressed gene in the selected clone, and its depletion suppressed the elevated sphere-forming capacity in vitro and tumorigenicity in vivo. Overall, the present study established an experimental strategy to isolate a malignant subpopulation from a CRC cell line. Additionally, results from the present model revealed that DPEP1 may serve as a promising prognostic biomarker for CRC.

All-optical diffractive neural networked terahertz hologram.

Holography has garnered an explosion of interest in tremendous applications, owing to its capability of storing amplitude and phase of light and reconstructing the full-wave information of targets. Spatial light modulators, metalenses, metasurfaces, and other devices have been explored to achieve holographic images. However, the required phase distributions for conventional holograms are generally calculated using the Gerchberg-Saxton algorithm, and the iteration is time-consuming without Fourier transform or other acceleration techniques. Few studies on designing holograms using artificial intelligence methods have been conducted. In this Letter, a three-dimensional (3D)-printed hologram for terahertz (THz) imaging based on a diffractive neural network (DNN) is proposed. Target imaging letters "THZ" with uniform field amplitude are assigned to a predefined imaging surface. Quantified phase profiles are primarily obtained by training the DNN with the target image and input field pattern. The entire training process takes only 60 s. Consequently, the hologram, that is, a two-dimensional array of dielectric posts with variational heights that store phase information, is fabricated using a 3D printer. The full-wave simulation and experimental results demonstrate the capability of the proposed hologram to achieve high-quality imaging in the THz regime. The proposed lens and design strategy may open new possibilities in display, optical-data storage, and optical encryption.