The creation of pseudo-magnetic fields in strained graphene has emerged as a promising route to investigate intriguing physical phenomena that would be unattainable with laboratory superconducting magnets. The giant pseudo-magnetic fields observed in highly deformed graphene can substantially alter the optical properties of graphene beyond a level that can be feasible with an external magnetic field, but the experimental signatures of the influence of such pseudo-magnetic fields have yet to be unveiled. Here, using time-resolved infrared pump-probe spectroscopy, we provide unambiguous evidence for slow carrier dynamics enabled by the pseudo-magnetic fields in periodically strained graphene. Strong pseudo-magnetic fields of ~100 T created by non-uniform strain in  graphene on nanopillars are found to significantly decelerate the relaxation processes of hot carriers by more than an order of magnitude. Our findings offer alternative opportunities to harness the properties of graphene enabled by pseudo-magnetic fields for optoelectronics and condensed matter physics. The effect of strain-induced pseudo-magnetic fields on the optical properties of graphene has not been experimentally explored yet. Here, pseudo-magnetic fields reaching values of 100 T are shown to increase by more than an order of magnitude the relaxation lifetime of hot carriers in periodically strained graphene. Among the surprising properties is its exceptional mechanical strength4, which has spurred intense research activity on strain engineering of graphene5. Approximately a decade ago, the creation of gauge fields in graphene by harnessing non-uniform strain began attracting considerable attention as a potential route towards realizing previously unattainable physical properties in graphene6. Particularly, a theoretical study predicted that a uniquely designed strain in graphene could induce pseudo-magnetic fields that would allow electrons to behave as if they were subjected to a strong real magnetic field7. The strength of pseudo-magnetic fields in strained graphene can be orders of magnitude higher than the strength of external magnetic fields generated by superconducting magnets10, thus prompting researchers to experimentally verify the existence of such pseudo-magnetic fields. Since then, scanning tunneling spectroscopy (STS) measurements have repeatedly confirmed that pseudo-magnetic fields in mechanically deformed graphene can reach up to a few hundred T16. These giant pseudo-magnetic fields can form significant energy gaps7 and substantially modify optical transitions in the same manner as an external magnetic field20, but to a previously unattainable extent due to the high strength of pseudo-magnetic fields. However, the influence of pseudo-magnetic fields on the optical properties of graphene has not yet been experimentally verified.Since its discovery in 2004In this article, we present an experimental observation of the effect of pseudo-magnetic fields on hot carrier relaxation processes. The strain engineering platform employed in this study allows creating a non-uniform strain distribution with a maximum strain field of ~3.5% that is higher than other reported values for sustainable strain in graphene. The magnitude of the induced pseudo-magnetic fields is confirmed to be ~100 T via rigorous tight-binding simulations combined with the elasticity theory. Using time-resolved infrared pump–probe spectroscopy combined with theoretical modeling based on many-body interactions, we experimentally confirm that the induced pseudo-magnetic fields in our strained graphene system can decelerate the hot carrier relaxation processes by more than an order of magnitude.25. Graphene’s excellent mechanical property4 allows the accumulation of a large tensile strain at the edges of nanopillars10. The resultant non-uniform strain distribution near the edges of nanopillars can generate strong pseudo-magnetic fields, which force electrons to move in a circular motion as if they are under a strong external magnetic field8. Due to the preserved global time-reversal symmetry under the influence of strain-induced pseudo-magnetic fields, electrons in the K and K′ valleys experience pseudo-magnetic fields of opposite signs, thus circulating in opposite directions12. This cyclotron motion of the charge carriers corresponds to the creation of pseudo-Landau levels . Figure x and y directions as shown in the middle (26 (see Methods). This discrepancy between the simulated and measured maximum strain values is attributable to the inherent resolution limit of the Raman measurement with the diffraction-limited laser spot size21. By performing convolution on the simulated atomic-scale strain distribution by using a two-dimensional Gaussian corresponding to the spot size of the laser beam21, a realistic strain distribution that could be optically measured on the nanopillar was deduced, yielding a maximum strain value of 1.32%  at the atomic scale , a0 is the nearest carbon–carbon bond length (~0.14 nm), and 16, thus ensuring the reliability of our simulation (see Supplementary Note 4 for more details on the pseudo-magnetic field simulation). As shown in Fig. 10.Figure ift Fig.  by using32% Fig. . A compaale Fig.  was obtaR/R), which is directly proportional to the absorption in graphene for monolayer devices30. The measurement was performed at 4 K, unless stated otherwise, and low pump fluence (<1 mJ cm−2) was used to avoid any heating effect (see Methods for details). The probe pulse spot size was approximately 10 × 10 μm2, thus allowing us to probe a large number (>16) of highly identical nanopillars simultaneously for a large effective area possessing sizable pseudo-magnetic fields. The strength of pseudo-magnetic fields is negligible in graphene placed on flat surfaces . Figure ces Fig.  where thces Fig. , which ines Fig. , left exnes Fig. , right, λpump ~1030 nm) relax to the lower energy states rapidly within a few tens of femtoseconds through electron–electron scattering, thus inhibiting the absorption of probe pulses at the corresponding energy (λprobe ~1450 nm) due to Pauli blocking43. This decreased absorption in the control device was reflected in the rapid rise of the negative reflection change (−ΔR/R) . A subsequent slow relaxation process with a very weak intensity via the emission of acoustic phonons40 can also be observed in our sample, but only at higher pump fluences. In this study, we focused on the initial rapid carrier relaxation processes because of their importance in various crucial device applications49.To better understand the carrier dynamics of the device on nanopillars possessing pseudo-magnetic fields, we first performed control experiments involving the same monolayer graphene sheet on an entirely flat surface without nanopillars. In pristine graphene with massless Dirac cones Fig. , left, t2O3) to avoid any unexpected effects from substrate phonons51, which may influence the carrier dynamics. Immediately after pump excitation, −ΔR/R of the nanopillar device quickly rose and decayed on the same time scale as that of the control device. Surprisingly, −ΔR/R rose again very slowly until ~700 fs, followed by a slow decay with a time constant of ~1.66 ps. To illustrate the two distinct regimes, a detailed view over a shorter time range is shown in the inset of Fig. R/R in the rapid regime can be clearly attributed to pristine graphene with fast carrier relaxation processes . The carrier dynamics can be well captured by the Boltzmann-like scattering equation57, which is the effective theoretical tool to study the thermalization of hot carriers after pump excitations (see Supplementary Note 7 for more details).Optical Bloch equations based on many-body interactions were used to quantitatively understand the relaxation dynamics of charge carriers under the influence of pseudo-magnetic fields. The main many-body interaction process considered in the modeling was the electron–electron scattering that is the dominant relaxation mechanism in Landau-quantized grapheneR/R)  Fig.  because /R) Fig. , thus pr44 and highly efficient hot electron harvesting devices35. The light emission58 and population inversion properties46 in graphene can be improved drastically by slowing down the hot carrier relaxation processes through pseudo-magnetic fields.In summary, we have presented an experimental observation of the effect of pseudo-magnetic fields on the carrier relaxation processes in highly strained graphene. Our periodic nanopillar structure array achieves strong pseudo-magnetic fields of up to 100 T, which play a major role in enabling the observation of an extended hot carrier relaxation lifetime by more than an order of magnitude. The pseudo-magnetic field-induced slow carrier dynamics in highly strained graphene poses crucial implications towards the realization of a new class of graphene-based optoelectronic devices, including pseudo-Landau level lasers8. This design with uniform pseudo-magnetic fields may allow addressing individual Landau level transitions under a specific pseudo-magnetic field strength. Another disadvantage of graphene under pseudo-magnetic fields is that energetically degenerate transitions cannot be optically selected via circularly polarized radiation, while, for pristine graphene under real magnetic fields, circularly polarized radiation can selectively excite only one of two degenerate transitions33. Instead, we propose a possibility to harness a valley degree of freedom in strained graphene. As shown in Supplementary Fig. 49.One constraint of our nanopillar structure is that the obtained pseudo-magnetic field is spatially varying, thus inhibiting us to study the isolated effect of specific pseudo-magnetic field strength on the carrier dynamics. In Supplementary Fig. 59. In contrast, our nanopillar devices with highly strained graphene under pseudo-magnetic fields may possess disorder-assisted relaxation channels , which may dominate the carrier cooling process at a longer time scale59. A further study on the effect of symmetry-breaking supercollisions on the carrier dynamics at a longer timescale may provide further insights towards building pseudo-Landau-quantized graphene devices. By presenting experimental evidence of the effect of pseudo-magnetic fields, our finding offers a new landscape of opportunities towards creating pseudo-magnetic field-based graphene optoelectronic devices.It is also worth noting that for the cooling process at a longer timescale, optical phonons hardly fulfill the energy conservation and the momentum conservation in Landau-quantized graphene systems in external magnetic fields2/Si substrate using Raith e-line e-beam lithography system built in field-emission SEM (JEOL JSM-7600F). The substrate was then dipped in BOE  for 3 min 30 s at room temperature, followed by atomic layer deposition (ALD) for depositing a 20-nm Al2O3 layer on the entire substrate. The fabricated nanopillars have the lateral size of 300 nm -based wet-etching process. For an etching mask , we patterned polymethyl methacrylate resist  on SiO2, 512 × 512 pixel2 and 0.5 Hz, respectively. For Raman spectroscopy characterization, a 532-nm excitation laser was used along with a 100× objective lens. During the measurement, additional care was taken to keep the laser power low enough to avoid any heating effect. The strain-shift coefficient of 65.4 cm–1/%26 was used to estimate the maximum strain of 1.3% in our nanopillar device. The theoretical limit of spatial resolution  of our Raman system can be calculated using Abbe’s diffraction limit:λ is the wavelength of the excitation laser, and NA is the numerical aperture of the microscope objective. In our experiment, we used a 532-nm laser with a 0.90/100x objective lens, resulting in a spatial resolution limit of 361 nm.To analyze the structural characteristics and strain distribution of our nanopillar devices, we used a field-emission SEM , AFM , and Raman spectroscopy . The electron acceleration voltage in SEM was set to 10 kV. AFM measurement was performed on nanopillar sample in tapping mode. The scan size, resolution, and speed were set to 10 × 10 μmλprobe = 1450 nm) centered at the same spatial position. The spot size of pump and probe pulses were approximately 100 × 100 μm2 and 10 × 10 μm2, respectively. A pump fluence was approximately 0.4–1 mJ cm–2, which was adjusted by a continuously variable neutral density filter.Femtosecond pump–probe measurement was performed in reflection geometry. The sample was held in a closed-cycle helium cryostat . The pump pulses were generated from a femtosecond laser with a 230-fs pulse duration . The differential reflectance change was measured with a probe pulse  and final states . For the carrier–optical phonon scattering part, the scattering rate can be written as32:p, which is determined by Bose–Einstein distribution, and The main carrier dynamics mechanism we present in this study can be described by the Boltzmann-like scattering equationSupplementary Information


TAR DNA-binding protein 43 (TDP-43) is a highly conserved nuclear RNA/DNA-binding protein involved in the regulation of RNA processing. The accumulation of TDP-43 aggregates in the central nervous system is a common feature of many neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Alzheimer’s disease (AD), and limbic predominant age-related TDP-43 encephalopathy (LATE). Accumulating evidence suggests that prion-like spreading of aberrant protein aggregates composed of tau, amyloid-β, and α-synuclein is involved in the progression of neurodegenerative diseases such as AD and PD. Similar to those of prion-like proteins, pathological aggregates of TDP-43 can be transferred from cell-to-cell in a seed-dependent and self-templating manner. Here, we review clinical and experimental studies supporting the prion-like spreading of misfolded TDP-43 and discuss the molecular mechanisms underlying the propagation of these pathological aggregated proteins. The idea that misfolded TDP-43 spreads in a prion-like manner between cells may guide novel therapeutic strategies for TDP-43-associated neurodegenerative diseases. Further research is needed to determine how an aggregate-forming protein common to several neurodegenerative disorders propagates throughout the brain. Many neurodegenerative conditions involve aggregates created by ‘prion-like’ proteins, misfolded proteins that can confer their abnormal structure on neighboring healthy proteins, resulting in aggregates which spread rather like an infection. Hyung-Jun Kim at the Korea Brain Research Institute in Daegu, South Korea, and co-workers reviewed current understanding of the transactive response DNA-binding protein 43 (TDP-43), an aggregate-forming protein implicated in disorders such as Alzheimer’s disease and frontotemporal dementia. Growing evidence suggests that TDP-43 may spread in a prion-like fashion. TDP-43 is implicated in the onset of Alzheimer’s, and the spread of misfolded TDP-43 aggregates is closely tied to disease severity. More research is needed into how TDP-43 propagates in different tissues and central nervous system cells. Each of these diseases is associated with misfolding of specific proteins. For example, the main proteins comprising pathological deposits in AD are amyloid-β and tau5. α-Synuclein is the major component protein of pathological deposits in PD7. Furthermore, TAR DNA-binding protein 43 (TDP-43) aggregates are frequently observed in multiple diseases, such ALS, FTD, AD, and LATE10.Amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), frontotemporal dementia (FTD), Alzheimer’s disease (AD), and limbic predominant age-related TDP-43 encephalopathy (LATE) are common neurodegenerative diseases with an increased prevalence in aging societies. Although the clinical symptoms of these diseases are different, they share a similar pathological feature. The formation and accumulation of pathological inclusions composed of abnormal aggregated proteins in affected tissues is one of the hallmarks of these neurodegenerative diseasesTARDBP gene and belongs to the heterogeneous nuclear ribonucleoprotein (hnRNP) family. In normal cells, TDP-43 is mainly present in the nucleus and plays important roles in RNA regulation, such as transcriptional regulation, alternative splicing, and mRNA stabilization13. Under pathological conditions, cleavage, hyperphosphorylation and ubiquitination of TDP-43 can occur16. These posttranslational modifications lead to cytoplasmic accumulation and aggregation of TDP-43. In particular, phosphorylation of TDP-43 at serine 403/404 and 409/410 (p-TDP-43) can result in the pathological inclusions observed in TDP-43 proteinopathies18.TDP-43 is a ubiquitous protein that is encoded by the 21. These so-called ‘prion-like’ proteins have a common domain that can induce misfolding and self-aggregation24. It has also been revealed that such pathological proteins can play roles as seeds that can be propagated to other nearby cells in various ways to serve as templates for creating new aggregates. Extensive research has shown that amyloid-β, tau, and α-synuclein aggregates can induce native protein misfolding and cell-to-cell transmission both in vitro and in vivo31. Similarly, while evidence of a prion-like mechanism of amyloid-β, tau, and α-synuclein aggregation has been reported for over a decade, the mechanism of TDP-43 propagation is relatively unknown.Recently, several studies have been conducted on the propagation of these misfolded pathological proteins based on clinical evidenceIn this review, we focus on evidence of spreading TDP-43 pathology in several neurodegenerative diseases and summarize the published experimental studies supporting cell-to-cell propagation of TDP-43 both in vitro and in vivo.33. Mutations of the nuclear localization sequence (NLS) in the NTD are the cause of cytoplasmic localization and aggregation of TDP-4334  and glycine, and their sequence properties are similar to those of yeast prion proteins. The prion-like domain plays a key role in regulating the solubility and folding of proteins. Proteins containing prion-like domains undergo phase separation into membraneless, spherical compartments38. The liquid–liquid phase separation of TDP-43 is influenced by both hydrophilic and hydrophobic residues. The presence of mutations or aberrant posttranslational modification leads to the formation of irreversible aggregation via liquid–solid phase separation39. Many mutations in the TDP-43 gene have been found to be associated with ALS and FTLD, and most disease-associated mutations are located within the C-terminal domain41. In particular, in several models, these mutations in the C-terminal domain of TDP-43 can promote the intrinsic aggregation of TDP-43. The expression of TDP-43 mutations, including Q331K, M337V, Q343R, N345K, R361S, and N390D, has been shown to increase aggregation and cell toxicity in yeast cells41, and other disease-associated mutations, such as G294A, Q331K, M337V, Q343R, N390D, and N390S, enhance protein aggregation when expressed in SH-SY5Y cells42. In a Drosophila model, the expression of mutant TDP-43 A315T has been shown to increase protein aggregation and neurotoxicity43. In addition, various peptides bearing pathogenic TDP-43 mutations, such as G294V, G294A, and G295S, have been found to form twisted amyloid-like fibers44. Therefore, the CTD domain of TDP-43 is the most relevant region of the protein for its aggregation.TDP-43 is composed of an N-terminal domain , two RNA recognition motifs , and a C-terminal domain . The NTD region contains a ubiquitin-like fold with one α-helix and six β-sheets and promotes TDP-43 self-oligomerization in a concentration-dependent manner45. However, under stress conditions such as heat shock, oxidative stress and arsenite exposure, the cytoplasmic transfer of nuclear TDP-43 increases, and cytoplasmic TDP-43 accumulates to form stress granules (SGs) with several other proteins and RNAs49. When stress dissipates, SGs containing TDP-43 disassemble, and TDP-43 released from SGs translocates into the nucleus50. However, chronic stress evokes prolonged SG formation, which leads to persistent accumulation of cytoplasmic TDP-43 aggregates.Normally, TDP-43 is predominantly localized in the nucleus, but it also shuttles between the nucleus and the cytoplasm to carry out diverse cellular functions. The level and localization of TDP-43 is finely regulated via a negative-feedback mechanism4C2)30 RNA. (G4C2)30 RNA also disrupts the structure of the nuclear membrane51. Moreover, other nuclear membrane proteins, such as Nup62 and Kpnb1, are associated with the cytoplasmic accumulation of TDP-4352. In addition, cytoplasmic aggregates of TDP-43 can directly induce the disruption of nucleocytoplasmic transport and nuclear pore complexes54. TDP-43 aggregates induce the mislocalization and aggregation of nucleoporins and transport factors. TDP-43-induced impairment of the nuclear pore complex accelerates cytoplasmic mislocalization and accumulation of TDP-43, subsequently contributing to neuronal dysfunction and toxicity.In addition to dysregulation of SG formation, dysfunction of the nuclear pore complex is also related to cytoplasmic mislocalization and aggregation of TDP-43. Several studies have reported that the cytoplasm–nucleus gradient of Ran, the major regulator of nuclear localization of TDP-43, is reduced by the expression of  immunoreactivity in the amygdala was detected in a higher percentage of AD patients than normal subjects. p-TDP-43 deposition progresses to the entorhinal cortex and subiculum, which are next to the occipitotemporal cortex and dentate gyrus of the hippocampus, followed by the temporal cortex, substantia nigra, midbrain, inferior temporal cortex, basal ganglia, and middle frontal cortex66. TDP-43 pathology stages 1–5 are associated with impairment of episodic, semantic, and working memory, perceptual speed and visuospatial ability are related to TDP-43 accumulation in AD67.AD is a progressive neurodegenerative disease and the most common type of dementia. Amyloid-β or tau deposition is generally regarded as a major cause of the pathogenesis of AD. However, recent studies have revealed that TDP-43 is closely related to the onset and development of AD70 or distant cell-to-cell transmission19. Recently, a consensus working group published new terminology and diagnostic criteria for undefined neuropathology entities, LATE, and limbic predominant age-related TDP-43 encephalopathy neuropathological change (LATE-NC). The research group examined whether some patients diagnosed with AD do not exhibit accumulation of amyloid-β protein through a postmortem study. This study revealed that accumulation of TDP-43 protein but no accumulation of amyloid-β protein was observed in patients with AD-like symptoms. Excessive accumulation of TDP-43 leads to cognitive disorders, and 20–50% of patients aged 80 or older have sufficient levels of TDP-43 aggregates to induce cognitive disorders. In LATE-NC, which differs from FTLD-TDP in the region affected, the distribution of TDP-43 pathology is relatively limited. TDP-43 aggregates are found only in the amygdala in the first stage of LATE and are present in the amygdala and hippocampus in the second stage. TDP-43 inclusions are found in the amygdala, hippocampus, and middle frontal gyrus in the third stage71. TDP-43 pathology in LATE patients is associated with the same mechanism of cell-to-cell transmission described above.Previous studies have suggested that the propagation mechanism of TDP-43 in AD involves direct cell-to-cell transmission73. In particular, behavioral variant FTD (bvFTD) patients have widespread and severe TDP-43 pathology. The spread of p-TDP-43 pathology was divided into four stages based on the findings of a clinical cohort study. In the first stage, p-TDP-43 inclusions are widespread in the basal and anterior portions of the prefrontal neocortex  and amygdala. In stage 2, an increased p-TDP-43 burden is observed in the anteromedial area, superior and middle temporal gyri, striatum, and medial and lateral portions of the thalamus. In more advanced cases, a third stage with involvement of the motor cortex, neocortical areas, and spinal cord anterior horn is observed. In stage 4, the p-TDP-43 inclusion burden spreads to the occipital neocortex region, the visual processing center of the brain75. p-TDP-43 lesions in FTD have been associated with various behavior, language, and functional abilities and are closely connected to the prefrontal cortex, limbic structures , and striatal regions77. Moreover, the spreading pattern of FTD is similar to that of ALS, possibly indicating a common molecular mechanism among p-TDP-43 proteinopathies20. p-TDP-43 pathology spreads to distinct parts of the brain through the major axonal pathway via cell-to-cell transmission as described above.FTLD is a progressive and fatal neurodegenerative disease characterized by deficits in behavior or language skills associated with degeneration of the frontal and anterior temporal lobes. FTLD patients have a characteristic histopathology with cytoplasmic inclusions containing aggregated TDP-43 or tau protein in neurons and glial cells. FTLD is classified into different pathological subtypes, including FTLD with tau-positive inclusions (FTLD-tau), FTLD with FUS-positive inclusions (FTLD-FUS), and FTLD with TDP-43 and ubiquitin inclusions (FTLD-TDP). Although TDP-43 mutations are associated with a very low percentage of FTLD cases, TDP-43-positive cytoplasmic inclusions are present in up to 50% of FTLD patientsTARDBP. Although a small proportion of sporadic ALS and fALS cases are associated with TDP-43 mutations, TDP-43 pathology can be observed in more than 90% of ALS patients78.ALS  is the most common motor neuron degenerative disease and is characterized by progressive degeneration of both upper and lower motor neurons. Less than 10% of ALS cases are familial ALS (fALS), and ~4% of fALS cases are caused by mutations in the gene encoding 81. These clinical features may evidence for the cell-to-cell propagation of TDP-43.The initial symptoms of ALS can be fairly diverse in different people and can be found in specific parts of the body. The symptoms also tend to be asymmetrical. As the disease progresses, the symptoms generally spread from one side to both sides of the body. In addition, the progression rate of ALS can be quite variable from one person to another. The severity of motor neuron loss is also related to the site of disease onset. Although not all people with ALS experience the same symptoms or the same sequence or progression pattern, progressive muscle weakness and paralysis are universally experienced82. Clinical observations of ALS patients have shown that ALS progression is characterized by an increase in p-TDP-43 lesions as well as the degeneration of motor neurons82. Several studies have revealed that p-TDP-43 aggregates are sequentially propagated in axons of somatomotor neurons via axonal transport83. Axonal transport is therefore thought to have an essential role in p-TDP-43 pathology in ALS, possibly through the corticospinal tract. However, the molecular mechanisms of p-TDP-43 pathology must be elucidated in future studies.According to studies by Brettschneider, J. et al. (2013) and Braak, H. et al. (2013), ALS can be divided into the following four stages. In stage 1, p-TDP-43 inclusions mainly occur in the projection neurons of the agranular motor cortex and in the somatomotor neurons of the brainstem and spinal cord. In stage 2, p-TDP-43 aggregates are observed in the prefrontal cortex, reticular formation, precerebellar nuclei of the brainstem, and parvocellular portions of the red nucleus. In stage 3, p-TDP-43 pathology develops in the prefrontal cortex, striatum, and basal ganglia. In stage 4, p-TDP-43 pathology extensively progresses into the anteromedial areas of the temporal lobe and entorhinal cortex and in the hippocampal and dentate fascia84, TDP-43 was fused to the N-terminal or C-terminal half of luciferase constructs named TDP-L1 and TDP-L2, and luciferase activity was detected if TDP-L1 and TDP-L2 interacted. Conditioned medium from HEK293 cells transiently transfected with TDP-43 fused to luciferase or TDP-L1 and TDP-L2 was collected after 72 h and centrifuged to eliminate floating cells and cell debris. Native HEK293 cells were cultured in conditioned media for 72 h, and luciferase activity was measured in recipient cells after extensive washing. The results showed intracellular uptake of TDP-43 aggregates from the medium and were confirmed in primary mouse cortical neurons using an rAAV6.2 viral vector harboring TDP-L1 and TDP-L2. In addition, to determine whether TDP-43 is transmitted by microvesicles/exosomes (MVEs), HEK293 cells were transfected with Myc-tagged TDP-43. Then, MVEs were collected after 72 h. Western blot analysis confirmed the presence of Myc-tagged TDP-43 in the MVEs. In addition, researchers performed microfluidic culture system experiments to examine the possible uptake and transmission of TDP-43 by axon terminals. This experimental technique allowed the culture of neuronal cell bodies fluidically isolated from their axon terminals. Conditioned medium from HEK293 cells transfected with TDP-Luc was added to the axon terminals for 5 days. Then, luciferase activity was detected in lysates of primary cortical neuronal soma from the opposite chamber. The hypothesis that intracellular TDP-43 aggregates can be released through exosomes was also confirmed in another study85. The presence of TDP-43 in the exosomal fractions of SH-SY5Y cells expressing TDP-43 and treated with/without brain insoluble lysates from ALS patients was detected by immunoblot analysis.Conditioned medium experiments have been used to investigate the possible transmission of cell-derived TDP-43. In a study published by Feiler et al.86. Similar results have been reported in other papers87. These researchers used wild-type TDP-43 and mutant TDP-43 with a dysfunctional nuclear localization signal (ΔNLS) construct and HEK293 cells to obtain conditioned medium. Then, recipient cells, HEK293 cells, and primary mouse spinal cord neurons were incubated with conditioned medium for 20 h. Immunofluorescence staining and immunoblotting of the recipient cells showed no signs of propagation of TDP-43.However, in another published study using conditioned medium, researchers were unable to detect TDP-43 aggregates in cells incubated with conditioned medium for 3 daysThese discrepant results from experiments using conditioned media may have resulted from differences in the TDP-43 constructs, cell type, and incubation time. Therefore, more research on the propagation of TDP-43 released by cells is required.85. After 3 days, DsRed-transfected cells and TDP-43-transfected cells were mixed at a 1:1 ratio and grown for an additional 3 days. Then, the cells were stained with an anti-pTDP-43 S409/410 antibody and observed by confocal laser microscopy. TDP-43 aggregates were observed in the cytoplasm of DsRed-expressing cells. The proportion of DsRed and phosphorylated TDP-43 double-positive cells was calculated to be 2.9%. The presence of phosphorylated TDP-43 aggregates in cells expressing DsRed indicated that p-TDP-43 aggregates propagated to adjacent cells that originally did not have TDP-43 aggregates. Similar results have been confirmed in other papers86. In another study84, in a coculture system, TDP-43 was fused to the N-terminal or C-terminal half of VenusYFP (constructs named TDP-V1 and TDP-V2), and VenusYFP fluorescence was observable by microscopy if TDP-V1 and TDP-V2 were oligomerized. Separate cultures of HEK293 cells were transfected with either TDP-V1 or TDP-V2. After 48 h, each transfected cell line was trypsinized and washed, and the cells were coplated at a 1:1 ratio and cocultured for an additional 48 h. After 2 days, cytoplasmic VenusYFP fluorescence was detected in the cocultured cells. This observation indicated that TDP-V1 and TDP-V2 were transferred between cells. In addition to experiments involving fluorescence image analysis methods using microscopy, studies evaluating TDP-43 propagation through single-cell analysis based on flow cytometry have recently been conducted89. Before flow cytometry, SH-SY5Y ‘recipient’ cells were stably transfected with GFP, and SH-SY5Y ‘donor’ cells were transfected with HA-tagged TDP-43 using the CMV lentiviral system. Equal amounts of recipient cells and donor cells were cocultured for 3 days. The percentage of GFP+ and HA+ (Cy5) cells was measured by flow cytometry, and there was a significant 1% increase in the percentage of double-positive cells 3 days after coculture compared with time point zero88. Furthermore, in a recently published paper, NSC-34 cells were transiently transfected with either wild-type TDP-43-tdTomato or mutant TDP-43 G294A-tGFP. Transfected cells were cocultured at a 1:1 ratio, and 24 h later, they were analyzed using flow cytometry. Cell-to-cell transfer was quantified as the percentage of tGFP and tdTomato double-positive cells. More than 10% of the transfected cells contained both tGFP and tdTomato89.It is also possible that TDP-43 undergoes cell-to-cell transfer through contact between cells. To confirm whether TDP-43 aggregates can be propagated between cells, contact coculture experiments were performed. Human neuroblastoma SH-SY5Y cells were transfected with a DsRed or TDP-43 vector85. Two other studies using brain tissue from ALS patients also showed a seeding effect of insoluble TDP-43. Cortex-derived ALS patient samples, but not cerebellum-derived samples, induce TDP-43 oligomerization in primary cultured neurons84. Western blotting of HEK293 cells cotransfected with p-TDP-43 extracts from the brains of ALS patients and the full-length TDP-43 construct revealed pathological p-TDP-43 bands. However, HEK293 cells transfected with only brain extracts did not exhibit TDP-43 pathology86. Recently, a research group developed a new simple method for pathological TDP-43 extraction, SarkoSpin90. By coupling the SarkoSpin method and mass spectrometry, these researchers identified a subset of insoluble proteins beyond TDP-43 in the FTLD subtype. To determine whether there are differences in cell toxicity between types of FTLD-TDP, a cell toxicity assay was performed on mouse primary cortical neurons using SarkoSpin pellets from patients with different disease subtypes. Cell viability was significantly lower after inoculation with FTLD-TDP-A extracts than after inoculation with control or FTLD-TDP-C extracts. Moreover, whether the observed neuronal toxicity is dependent on the aggregation of endogenous TDP-43 was evaluated. p-TDP-43 aggregates extracted from FTLD-TDP-A patients, but not from FTLD-TDP-C patients, were shown to induce endogenous TDP-43 aggregation, potentially via protein seeding.Several studies have been carried out to investigate whether insoluble TDP-43 derived from the brain tissues or cerebrospinal fluid (CSF) of ALS or FTLD-TDP patients as a seed can form intracellular inclusions. Prion-like proteins propagated from surrounding cells can play a role as seeds and can induce protein aggregation in healthy cells. SH-SY5Y cells were transiently transfected with HA-tagged TDP-43 and transduced with sarkosyl-insoluble faction containing TDP-43 aggregates prepared from the brain tissues of ALS or FTLD-TDP patients. After 2 days of transduction, intracellular TDP-43 aggregation in SH-SY5Y cells was observed by immunoblot analysis and immunofluorescence analysis. In addition, this seeding activity of insoluble TDP-43 from the brains of neurodegenerative disease patients was stable against detergents, heat, and proteolytic digestion, and cell-to-cell transmission ability was maintained91. To examine whether TDP-43 aggregates can propagate via CSF, researchers established a CSF cell culture model using U251 cells. U251 cells were inoculated in DMEM containing 30% v/v CSF derived from ALS or FTD patients. After 21 days of CSF treatment, U251 cells showed a decreased rate of growth and morphological changes. The seeding activity of CSF from patients was also confirmed in this culture system. The formation of TDP-43 aggregates and the mislocalization of TDP-43 from the nucleus to the cytoplasm were observed in ALS-FTD-CSF-treated U251 cells. This finding indicates that CSF from ALS and FTD patients contains seeds for inducing TDP-43 aggregation in cells. Moreover, immunofluorescence staining showed that TDP-43 aggregates colocalize with tunneling nanotube (TNT)-like structures in CSF-treated cells. Therefore, propagation of TDP-43 between neighboring cells could be mediated via TNT.In addition to experiments using lysates of brain tissue derived from patients, research assessing TDP-43 propagation using CSF from ALS or FTD patients has been conducted92. The researchers first evaluated whether TDP-43 aggregates are secreted by exosomes in N2a cells. TDP-43 was detected in the exosomal fraction of N2a cells transfected with wild-type human TDP-43, disease-associated mutants (A315T and G348C), or 25 C-terminal constructs. TDP-43 was also detected in exosomes from primary cortical neurons. It has been confirmed that the secretion of exosomes, including the secretion of TDP-43, is controlled by autophagy, the proteasome and protein aggregation. N2a cells expressing hTDP-43 were treated with bafilomycin A1 (an autophagy inhibitor), MG132 (a proteasome inhibitor), or ethacrynic acid (an oxidative stress inducer), and as a result, increased secretion of exosomes was observed. In addition, exosomes from the postmortem temporal cortices of sporadic ALS patients with TDP-43 pathology contained more TDP-43 than exosomes from controls. These results indicate that TDP-43 is secreted with exosomes at higher levels in the brains of ALS patients than in the brains of normal controls. Researchers found that exosomes from ALS patients are internalized by N2a cells or HEK293 cells and that TDP-43 was redistributed in the cytoplasm. To determine whether exosome secretion can buffer TDP-43 aggregates, N2a cells expressing hTDP-43 and transgenic mice expressing genomic fragments encoding mutant TDP-43 A315T were treated with GW4896, an inhibitor of nSMase2 that can reduce exosome secretion. In an in vitro model, treatment with GW4896 reduced exosomal TDP-43 secretion and increased cytoplasmic TDP-43 aggregates. In a transgenic mouse model, GW4896 administration exacerbated abnormal behavioral phenotypes, such as deficits in recognition memory, in TDP-43 A315T mice. Moreover, the number of denervated neuromuscular junctions was increased by GW4896 administration in TDP-43 A315T mice. Therefore, the authors of this paper suggest that inhibition of the exosomal secretion of TDP-43 could reduce the spreading of TDP-43 pathology to other cells, but reducing exosome secretion of TDP-43 as a treatment strategy for ALS might provoke the opposite effect. In another published paper93, researchers demonstrated that TDP-43 aggregates in FTLD-TDP spread throughout the brain via cell-to-cell propagation using transgenic mice expressing human TDP-43 (CamKIIa-hTDP-43 NLSm). Brain-derived FTLD-TDP extracts were stereotaxically injected into the neocortex, hippocampus, and thalamus. At 1 month postinjection, p-TDP-43-positive neuronal cytoplasmic inclusions were detected in the neocortex and hippocampus. To further examine the propagation of TDP-43, the authors analyzed the distribution of p-TDP-43 in CamKIIa-hTDP-43 NLSm transgenic mice injected with FTLD-TDP extracts over time. There was an increase in TDP-43 pathology in wider areas of the contralateral cortex over time, indicating the time-dependent spread of TDP-43 pathology to sites distant from the injection site. Researchers have also demonstrated that endogenous TDP-43 acts as a seed and that TDP-43 pathology propagates over time in nontransgenic mice injected with brain-derived FTLD-TDP aggregates, although at a very low rate. These findings indicate that pathophysiological conditions affecting homeostasis and the accumulation of cytoplasmic TDP-43, such as cellular stress, may promote the seeding and propagation of TDP-43 pathology in the brain.As described previously, many experiments have been conducted to show that TDP-43 propagates in a cell-to-cell manner in a cell culture model. However, the evidence for TDP-43 spreading in an in vivo model is not sufficient. In a paper published in 2016, researchers attempted to confirm the results of the in vitro experiments in vivo in a mouse model94 and prion-like proteins, such as amyloid-β95, α-synuclein96, and tau97, propagate via exosomes. Another possible mechanism of TDP-43 protein propagation involves TNTs. TNTs have been reported to play a role in the spread of prion proteins98. In experiments using CSF from ALS-FTD patients, it has been confirmed that TDP-43 aggregates that form within one cell might enter the cytoplasm of neighboring cells through a TNT-like structure. Therefore, the mechanisms of other prion-like proteins may be applicable to TDP-43 aggregates (Fig. As previously described, the hypothesis that TDP-43 propagates to neighboring cells through exosomes is controversial. Although the opposite of the expected behavioral results have been observed, it has been shown that the aggregation and propagation of TDP-43 may also be regulated by the exosome pathway in vitro as well as in vivo. In addition, previous studies have revealed that prion proteinstes Fig. .Fig. 2Sc100. However, the molecular mechanism underlying TDP-43 propagation is still unclear. Thus, further in-depth studies are warranted to fully elucidate whether different propagation mechanisms occur in each of the various cell types in the central nervous system. Most previous studies have focused on the propagation of TDP-43 from neurons to neurons. However, TDP-43 is expressed in many tissues and cell types, including glial cells in the central nervous system. In particular, several studies have revealed that the overexpression of TDP-43 in astrocytes can induce non-cell autonomous neuronal toxicity101. Accordingly, the propagation of TDP-43 by glial cells may also have an important role in the progression of neurodegenerative diseases. Therefore, studies on glia-to-neuron TDP-43 propagation and neuron-to-glia TDP-43 propagation should be conducted.As summarized in this review, it is clear that the propagation of TDP-43 protein occurs in several neurodegenerative diseases. Indeed, accumulating evidence from clinical and basic research Table  indicate


Physiotherapists play a key role in today’s healthcare and are recognised as the professionals in charge of rehabilitation, prevention and risk reduction . ProfessThe translation/back-translation was made by the Delphi Method with three rounds which were performed until de adaptation of the instrument to the Portuguese culture was achieved. A group of five experts, all with master and PhD academic degree, all with more than 25 years as Physiotherapist and Portuguese as their first language were selected.In order to reach consensus on the translation of the instrument, 3 rounds were carried out using the Delphi method, thus allowing linguistic equivalence to be obtained. In the 1st round of the process regarding the physical therapist's part, a 92 questions questionnaire was sent to the experts. In the 2nd round 42 questions were held and in the 3rd and final round, 5 questions were translated. Regarding the patient's part of the questionnaire, in the 1st round 18 questions were sent and in the 2nd round the number decreased to 9 questions. Consensus was achieved at 2nd round. The level of minimum agreement in each item was set to 80%, ensuring good translation and adaptation for Portuguese culture.The aim of the study was achieved, and the linguistic translation was completed. As next step, it is needed to conduct validation of the instrument for Portuguese culture by performing a pre-test. The results of this content validation by experts will be useful to improve the standard of care, teaching and research in physiotherapy, based on a standardised instrument which allow to measure Portuguese Physiotherapists professionalism, and perform international benchmark as well.


A high temperature of RTA (300–700 °C) was applied to graphene under an argon atmosphere to form defects on sp2 carbon lattices. The density of defects proportionally increased with increasing the RTA temperature. Raman scattering results confirmed significant changes in sp2 bonding. After 700 °C RTA, ID/IG, I2D/IG, and FWHM (G) values, which are used to indirectly investigate carbon-carbon bonds’ chemical and physical properties, were markedly changed compared to the pristine graphene. Further evidence of the thermally-induced defects on graphene was found via electrical resistance measurements. The electrical resistance of the RTA-treated graphene linearly increased with increasing RTA temperature. Meanwhile, the NO2 response of graphene sensors increased from 0 to 500 °C and reached maximum (R = ~24%) at 500 °C. Then, the response rather decreased at 700 °C (R = ~14%). The results imply that rich defects formed at above a critical temperature (~500 °C) may damage electrical paths of sp2 chains and thus deteriorate NO2 response. Compared to the existing functionalization process, the RTA treatment is very facile and allows precise control of the NO2 sensing characteristics, contributing to manufacturing commercial low-cost, high-performance, integrated sensors.This paper demonstrates the enhanced NO Furtholecules , and ult [−1 K1)  can guar2 [2 [3 [2S [Based on the material properties as mentioned above, various graphene sensors for the detection of O2 , CO2 [122 [2 [3 ,14, H2S 2 [3 [2S , et cete2 [3 [2S  have bee2 [3 [2S , electri2 [3 [2S ,13, and 2 [3 [2S ,15. Howe2 and NH3 detection. Furthermore, they demonstrated that the defect sites could be energetically more favorable for functionalization or decoration with nanomaterials. Although the RIE technique is very facile and appropriate for mass production, the accumulated damage to carbon-carbon bonds and increased oxidation sites after ion bombardment process severely affected charge transport property, and as such, the responsivity was decreased.Recently, facile methods based on the formation of lattice defects (mostly vacancies) on graphene sensing channels were studied to improve the sensing performance ,16. Lee 2 gas sensors. The generated graphene defects were confirmed by Raman spectra before and after RTA treatment. The RTA-treated graphene showed a remarkable increase in electrical resistance at metal-graphene-metal (MGM) contacts. Meanwhile, the NO2 response of graphene sensors exhibited the maximum responsivity of 24% and the response time of 111 s after the RTA treatment at 500 °C, which is about a two-fold enhancement compared with pristine (not RTA treated) graphene sensor (14%/304 s). Our results suggest that the RTA treatment can be a breakthrough approach to improving the NO2 sensing characteristics at low cost, thus contributing to manufacturing commercial low-cost, high-performance, integrated sensors.This report successfully demonstrates a facile method of creating graphene defects via rapid thermal annealing (RTA) to improve the performance of NO2/Si substrate  was used without further treatment, and the customized RTA system  and Nd:YAG laser (λ = 532 nm) at room temperature. The laser power was kept below 1 mW and the grating was 2400 L/mm. Wire program (version 3.4) was utilized to precisely designate peak position and intensity.DC was applied under an argon atmosphere (Pressure: ~7.0 Pa). The sputtering continued for 7 min with a deposition rate of ~0.5 nm/s. The spacing and the thickness of the electrodes were 100 μm and 200 nm, respectively.A shadow mask was used in DC magnetron sputtering process  to construct interdigitated gold (Au) electrodes. During the sputtering, ~315 V2 responsivity of the graphene sensor was analyzed in the custom-built measurement system (the temperature of the sample stage was maintained at 150 °C to improve the sensor’s recovery performance). At first, dry air as a balance gas was injected at 1 VDC and maintained for 20 min to eliminate unwanted gases and water molecules in the chamber. Then, the NO2 valve was opened, and the total flow, including the balance and target gases, was 500 sccm. The change in electrical resistance in response to the NO2 adsorption was recorded through electrical feed-throughs connecting to a SourceMeter  and sent to Lab-view software via a GPIB-to-USB converter for data collection and analysis.The NO2/Si substrate was used without further treatment (a), and the rapid thermal annealing (RTA) process was utilized to generate defects in graphene lattices (b). Previously, the RTA process was reported as a tool for generating defects on single-walled carbon nanotube (SWCNT) walls [A schematic fabrication process of the defected graphene-based gas sensor is shown in T) walls ,18,19. T2 sensing performance of the fabricated device was measured in a custom-built measurement system (e). The used measurement system is further discussed in Subsequently, Au-electrodes were sputtered through a shadow mask to fabricate the metal-graphene-metal (MGM) structured device (d). Au is generally used as electrode material in graphene devices because of its low contact resistance with graphene . The ins−1 and 2700 cm−1, respectively). Particularly in the case of pristine graphene (upper), D peak (at 1350 cm−1) is very weak and the I2D/IG value is relatively high as ~4, demonstrating a defect-free graphene monolayer [2D and IG refer to the intensities of 2D peaks and G peaks, respectively). On the other hand, the RTA-treated graphene shows an increased D peak intensity with a decreased I2D/IG value as ~1 in its Raman spectrum (lower), demonstrating the RTA-generated defects. Furthermore, three typical parameters extracted from each Raman spectrum are compared regarding the graphene qualities in D/IG value increased from 0.024 to 0.065, meaning increased defect density after RTA treatment. Furthermore, the I2D/IG value decreased from 4.1 to 1.0, and the FWHM(G) value increased from 14.5 to 18.6 . These parameters are generally utilized for evaluating the graphene quality, and all the parameter value changes demonstrated the degradation of graphene quality, implying the increased defect density of graphene [onolayer   [attices) ,18,19, sattices) .2 gas sensing performance of the fabricated device was studied. The expected NO2 sensing mechanism of the defected graphene device is described in 2 molecules adsorb onto the graphene surface, the concentration of major carriers  increases by the following reaction [Additionally, NOreaction .NO2→NO22 molecules is promoted, which enhances the NO2 response. The resistance change can be explained by the Fermi level shift  are locally electron-abundant due to the presence of oxygen-containing functional groups  . Thus, a2 sensors . The gray areas indicate where the target gas is injected. Here, the target- and base gases are 5 ppm NO2  and dry air, respectively, and 1 VDC was applied for each measurement. Additionally, the temperature of the sample stage was maintained at 150 °C during the measurement to improve the recovery performance. As the RTA temperature increased, the resistance of the corresponding device also increased. This is because the defect density increases as the temperature increases, as discussed above. However, in all the cases, the resistance decreased when the device was exposed to NO2 gas, meaning that all the device channels are p-type without polarity change.The time-dependent response curves are compared in gR and R0 are the minima- and maxima resistance values, respectively, in the area where target gas is injected. As the RTA temperature increases from 0 to 500 °C, the response of the corresponding device increases. However, the response somewhat decreases in the case of the RTA-treated sample at 700 °C. This phenomenon can be understood as the defect density increased as the RTA temperature increased, and the lattice structures were significantly damaged by high thermal energy at above a critical RTA temperature, resulting in deterioration of NO2 response.Here, off) can be reduced, and the response can be enhanced as well.In 2 gas molecules is promoted by the electron-abundant defected area as discussed above. However, the recovery times are almost the same for all the samples (~430 s), meaning that the RTA-generated defects do not affect the desorption rate of NO2 molecules.Additionally, each reaction curve’s response- and recovery times are compared b. The re2 sensors. As the RTA temperature increased from 300 to 700 °C, the corresponding device’s resistance gradually increased, whereas the NO2 response increased to 500 °C and decreased at 700 °C. This is because the defect density increased as the RTA temperature increased, and the graphene lattice is highly damaged above a critical RTA temperature, resulting in the deterioration of NO2 response. Interestingly, as the RTA temperature increased, the corresponding sensor’s response time decreased. The result implies that adsorption of NO2 molecules is promoted by the electron-abundant graphene defect areas. Our results suggest that the RTA process can be utilized to generate tunable graphene defects, and the defected graphene can be applied to high-performance gas sensor studies.In this paper, we demonstrated that graphene defects could be generated by RTA processes, and they could be utilized in high-performance NO


After 40 years of reform and opening-up policies, urbanization in China has significantly improved residents’ living standards; however, simultaneously, it has caused a series of health problems among Chinese citizens. Communities’ built environment is closely related to their residents’ health. However, few studies have examined the spatial differences in the health effects of community-built environments. Based on a 2013 health survey of residents in 20 communities in Wuhan, this study uses multilevel linear models to explore the effects of the built environment on residents’ health, analyzing the differences in its health-effect within different types of communities. The results showed that there were significant differences in the self-rated health status of residents in different communities, with those in high-end communities reporting a higher self-rated health status. The effect of the built environment on the health of residents in different communities was found to be inconsistent. For instance, the effect of the built environment on low-end community residents was very significant, but it was not obvious for residents in high-end communities. There are significant community-specific differences in the health- effect of the built environment: in high-end communities, residents’ health status was mainly restricted by travel accessibility, while in low-end communities, residents’ health status was mainly restricted by the accessibility of health facilities. Therefore, this paper proposes a built-environment optimization strategy for different types of communities to provide valuable insights for healthy community planning from a policy perspective. The rapid progress of urbanization and industrialization have significantly improved residents’ living standards; however, deteriorating urban environments threaten residents’ health ,2. AlthoAfter the housing reform, the urban housing paradigm changed from unit distribution to market circulation. The original multi-class dormitories and government offices began to collapse, while the commercialization of housing led residents of similar socioeconomic status to gather in similar communities; subsequently, the environmental differences between communities became increasingly obvious, and the residential space gradually showed a trend of stratification ,5.Unlike European and American countries, communities are subdivisions of urban streets and administratively formed towns in mainland China, and local governments have drawn geographical boundaries for communities. Residents’ committees are set up in communities as the grassroots management organizations in China. In Wuhan, for example, there are 13 municipal districts, 156 street offices, and 1431 community committees. Community is a spatial unit of residents’ daily lives, and the differences between its built environment and social environment may affect residents’ health status. However, few studies have explored the issue of community differences in the health-effect of the built environment, and it is difficult to provide adequate directives for the planning and construction of healthy communities.Therefore, based on the health survey data of community residents in Wuhan, this study uses multilevel linear models to discuss the following. (1) Are there any differences in the health status of residents in different types of communities? (2) How do the built environment’s elements affect residents’ health status? (3) Are there differences in the way the built environment affects health in different types of communities?Scholars from various countries have conducted a series of studies on the correlation betweem the built environment and health ,7,8. ForIn terms of community density, studies conducted in developed Western countries posit that a higher living density may promote residents’ physical activity, thus improving their health status . MedicalThe commercialization of housing has contributed to the stratification of living spaces, resulting in significant environmental differences in communities’ demographic structure, economic level, and health facilities . For exaWestern scholars have studied different types of communities and found that there are community differences in the effects of the economic level, demographic structure, and community environment on residents’ health . Fewer sAs an important city in central China, Wuhan has experienced rapid economic and social development; its urban space has been expanding, and its residential space has shown a distinctly heterogeneous pattern . The FifThe European five-dimension quality of life scale (EQ-5D) was used to measure health-related quality of life, including health-related behaviors, such as smoking, alcohol consumption, and physical activity. The Visual Analogue Scale (VAS) is a subscale of the EQ-5D used to measure the self-rated health status of the general population. The VAS shows respondents’ comprehensive evaluation of their self-rated health. A score of 100 represents the best health condition, and 0 represents the worst health condition.In this study, we used secondary data from the Fifth National Health Survey in Wuhan, conducted in September 2013, on 1922 residents in 20 communities  that werThe dependent variable in this study’s multilevel linear model is the residents’ self-rated health status level (continuous variable). The VAS score and utility value measure are important tools for describing residents’ quality of life, and their reliability and validity have been confirmed in prior studies . AlthougPersonal attributes were obtained from household survey data and community environment data from 2013, matching the time of the survey. The community environment was measured by taking the center of the community as a round point, and the appropriate distance of 800 m for residents’ daily activities as a radius , and theThis study uses residential characteristics as the basis for community evaluation and type classification to facilitate the exploration of community differentiation in the built environment, which affects residents’ health status. There are three main characteristics of residential types: architectural, neighborhood, and locational characteristics ,50,51. BSubsequently, the 20 analyzed communities were divided into two types: high-end and low-end. Among them, the 10 high-end communities included commercial houses with good location conditions and unit communities with good supporting facilities, whereas the 10 low-end communities included commercial houses, old unit communities, and old traditional neighborhood communities.The health status of residents is often influenced by both individual attributes and the community environment, thus forming a two-level nested structure of resident-community in the study data. However, existing empirical studies often use single-level regression models, such as multiple linear regression and structural equation models, which violate the assumption of mutual independence of variables in regression , ignore Therefore, this study uses a multilevel linear model to explore the spatial differences on the effects of the built environment on residents’ health using HLM 6.08 software. We first constructed three types of sample data: full sample, high-end community sample, and low-end community sample, and performed the following operations on each of the three types of samples. First, dummy variables were set for the categorical variables using SPSS26 software. Second, covariance detection was performed on the independent variables to exclude those that could not enter the model due to the presence of covariance. Third, the data were imported into HLM for Windows, version 6.08. Manufacturer: Scientific Software International, Inc. , and the null model analysis was conducted to determine the extent of between-group (community) differences and to assess the applicability of the multilevel linear model. Finally, the full model was constructed to explore the effects of each variable on residents’ health status at the individual attribute level and the community environment level.The full multilevel linear model equation is as follows:Resident-level regression equation:Community-level regression equation:i and j represent the resident and community levels, respectively; n indicates the number of resident-level variables; In the formula, p-value of 0.000, while the significance level was set at 0.05. This indicates that there are significant differences in the health status of residents in different types of communities.Regarding residents’ self-rated health status , the ave2. Additionally, 36% of respondents in the overall sample and 39.8% in high-end communities reported a housing area per capita of 30–60 m2. Lastly, 38.7% of respondents in low-end communities reported a housing area per capita below 30 m2.In terms of individual attributes, the percentage of women in the total sample was 54.2%. The average age of the residents surveyed was 47.7 years old, with most respondents (47.8%) being 40–60 years old. Compared with high-end communities, the proportion of elderly people (compared with that of young and middle-aged people) was significantly higher among residents of low-end communities. In the overall sample, 75% of respondents had a high school education or higher, while this value was 86% for high-end communities and 69.3% for low-end communities. Approximately 80% of respondents had medical insurance, but only 47.8% had undergone a medical checkup in the past year. The proportion of medical checkups was significantly lower in the low-end communities than in the high-end communities, which were 38% and 56.8%, respectively. Respondents’ average annual per capita household income was 39,900 CNY, with the highest percentage of respondents (39.3%) reporting an income between 10,000 and 30,000 CNY. The economic situation of residents in high-end communities was better, with 62% of them reporting an annual per capita household income above 30,000 CNY, while only 45.2% of respondents in the low-end communities reported such income. In terms of housing area per capita, respondents’ mean housing area per capita was 46.78 m2, while the density of medical facilities in high-end communities was significantly higher than that in low-end communities. The mean value of park square area was 8.3 ha, while that in high-end communities was 9.33 ha, and that in low-end communities was 7.28 ha. In terms of travel accessibility, the mean value of traffic station density in the sample communities was 6.01/km2, and the mean value of intersection density was 11.77/km2. Low-end communities have higher traffic station density and intersection density than high-end communities, which may be due to the fact that most of the low-end communities are historical communities that occupy a better location in the city due to their earlier construction [With regard to community attributes, all the indicators were continuous variables. In terms of the medical environment, the mean value of medical facility density in the buffer zone of the sample communities was 12.8 units/kmtruction . In termp-value of 0.000, indicating that the models passed the test and that the between-group variance (community) of each model was greater than its standard error, which indicates that the differences in the health status of the population originated largely from community differences [This study first constructed null models of the community-built environment with residents’ health status for three types of samples. Only the dependent variables were substituted, and no independent variables were substituted to determine whether the samples were suitable for multilevel linear models and to analyze the extent to which differences in residents’ health status originated from community differences. All three models were tested using the chi-square test with a ferences ; howeverferences . That isferences . The samThe analysis in Analysis of the full-sample regression results in For high-end communities, only three built-environment variables  were significantly associated with self-rated health status. Combining this finding with the ICC and between-group variance reduction ratios described above, it is clear that the self-rated health status of residents in high-end communities is less affected by the community’s built environment. This is because the residents of the high-end communities analyzed in this paper were mainly young and middle-aged people, who generally have higher income and education, as well as stable jobs, enjoy a wider social circle, have better travel ability, and more areas for activities, while the small-scale community built environment does not have a significant effect on this group ,64.Furthermore, in high-end communities, the density of traffic stops and intersections both had a significant positive effect on health status, suggesting that the self-rated health status of residents in high-end communities is mainly governed by accessibility . On the For low-end communities, all built environment variables, except for population density, had a significant effect on residents’ health status, and the regression coefficients were higher than those of high-end communities. Combining the ICC with the between-group variance reduction ratio, it is clear that the self-rated health status of residents in low-end communities is more influenced by the built environment around the community. Because of the limited radius of their daily activities, the most significant association with health status is the built environment around the community in a small area .All health facility variables had a significant positive effect on residents of low-end communities. The health status of residents of low-end communities was mainly governed by the accessibility of health facilities . Unlike Building density has a significant negative effect on the residents of low-end communities, while the floor area ratio had no significant effect.Among the health effects of the built environment, most of our findings are consistent with those of Western countries. However, some findings are of interest with regard to intersection density, building density, and floor area ratio. In contrast to prior Western studies , in this2, the residential land density is 70.5%, and the building density is 67.5%. With a floor area ratio of 2.63, the building density is extremely high and there is a noticeable lack of roads and public space, which produces a series of problems, such as overcrowding, air pollution, and noise pollution.Empirical studies in developed countries reveal that a high-density residential environment helps promote physical activity and reduces health risks among residents ,45. HoweOver the 40 years of rapid urbanization in China, the pattern of spatial differentiation of living space has been clearly formed. New urban areas have a good built-up environment and bring together a number of high-end communities. According to the descriptive statistics of the sample, most of these communities are high-volume/low-density commercial housing, and the building density is much smaller than that of the low-end communities, so there is no disadvantage of high building density . HoweverThe old city is also dotted with a lot of low-end communities. Based on the statistical description of the sample, most of these communities are low-volume/high-density and have a complex type of residence, a single type of land use, and a lack of activity space. High residential density not only affects the residents’ leisure-oriented physical activities and reduces their physical activity level but also hinders airflow and increases their exposure to air pollution .By comparing the residents of the two communities, we found that most of the residents of high-end communities are young and middle-aged, with good travel ability, less influenced by the surrounding built environment, and can travel to other areas of the city to obtain health resources. Their health status is also mainly governed by “travel accessibility.” In contrast, most of the residents of low-end communities are middle-aged and old, with limited travel ability, and are greatly influenced by the surrounding built environment. Their health status is mainly governed by “health facilities’ accessibility.” However, there are often fewer public service facilities, such as medical facilities, green areas, and squares, in the old city, resulting in health inequity.Through the above findings, we observe that: the ultra-high density of China’s big cities, the incomplete facilities, inadequate functions, and insufficient public and social services in old neighborhoods are urgent problems to be solved. At present, China’s urbanization process has shifted from high-speed development to high-quality development and from incremental planning-oriented to stock planning-oriented. Based on this, the Chinese government has been carrying out large-scale urban renewal and has issued guidelines for the construction of 15-min living circles and complete residential communities . The govA limitation of this study is that it uses the place of residence as the geographic context of residents to study the built environment based on their self-rated health.However, since the residents’ activity locations also include their workplaces, shopping places, and others, there is a deviation between the static residential units and the geographic context of their real experiences, creating an uncertain geographic context problem . TherefoIn this study, we used multilevel linear models to explore the influence of the built environment on residents’ health status in 20 communities in Wuhan, and analyzed the differences in the effect in different types of communities. The main findings are as follows: (1) There are significant differences in the health status of residents in different types of communities, as residents in high-end communities have higher self-rated health levels. (2) The extent to which the differences in residents’ health status originate from the community varies; a large proportion of the differences in the health status of residents in low-end communities and a small proportion of those in the health status of residents in high-end communities originated from the community itself. (3) The degree of influence of the community-built environment on residents of different types of communities is inconsistent; specifically, residents of low-end communities belong to more disadvantaged groups and have a more limited travel radius, while their health behaviors and health status are more significantly influenced by the community-built environment. Further, residents of high-end communities have higher socioeconomic status and travel ability, and the effect of a small-scale community-built environment on them is not obvious. (4) There were differences in the action of the community-built environment on the residents’ self-rated health status. Residents of low-end communities are mainly constrained by the accessibility of health facilities and building density, while residents of high-end communities are mainly influenced by the accessibility of travel and floor area ratio.Based on these findings, the conclusions of this study are as follows. A spatial differentiation pattern of living in Wuhan has clearly developed , and theWithin the context of urban renewal and the “Three Old” reform, we should strictly control building density, build pocket parks, administer the street space correctly, set up more community centers, improve the accessibility of health facilities, and provide residents with a high-quality food environment. Most of the high-end communities in this study comprised high-volume/low-density commercial housing, where residents have a relatively high socioeconomic status and their health conditions depend on travel accessibility. Therefore, following the perspective of urban incremental construction, land should be utilized in an appropriate and intensive manner , and the


Sarcoidosis‐lymphoma syndrome describes a pathological state wherein both sarcoidosis and lymphoma are present. Sarcoidosis and lymphoma may occur concurrently, or sarcoidosis may precede lymphoma. There are few reports which have previously described the temporal progression from lymphoma to sarcoidosis. Here, we present a patient with stage II diffuse large B‐cell lymphoma in the right breast. The patient achieved complete remission after chemotherapy. Five years after remission, the patient visited our clinic with newly developed enlarged mediastinal lymph nodes; lymphoma recurrence was suspected. However, mediastinal lymph node biopsy showed numerous noncaseating granulomas with no evidence of malignancy in the mediastinal lymph nodes. Consequently, a diagnosis of sarcoidosis was made. This case report highlights the need for pathological confirmation following biopsy when recurrence of lymphoma is suspected. We present a rare case of extremely delayed‐onset sarcoidosis mimicking mediastinal lymphoma recurrence after complete remission of diffuse large B cell lymphoma (DLBCL). Because CT and PET scans are insufficient for definitive diagnosis, pathological confirmation through biopsy is warranted when recurrence of lymphoma is suspected. Sarcoidosis and lymphoma are generally considered mutually exclusive diseases. However, in 1986, Brincker coined the term “sarcoidosis‐lymphoma syndrome” (SLS) to describe their occasional association.Here, we present a case of delayed sarcoidosis onset five years after complete remission (CR) of lymphoma.In October 2013, a 52‐year woman visited our hospital with a palpable breast mass. A right breast biopsy revealed medium to large‐sized monomorphic malignant lymphoid cells with CD 20 positivity Figure . The patFive years after CR, the patient returned to the clinic when chest CT scan showed enlarged mediastinal lymph nodes Figure . Her bloNo ethical committee approval was required for this case study, which is in compliance with institutional and national policies. The patient consented to the publication of clinical details and images concerning the case.Several common features of SLS have been previously described in the literature. Overall, lymphoma is observed 5.5 times more frequently in patients with sarcoidosis than in the general population.Sarcoidosis is a systemic disease characterized by granulomatous inflammation in affected organs. The pathogenesis of pulmonary sarcoidosis involves antigen presentation followed by CD4+ activation in regional lymph nodes, and subsequent organization of macrophages into granulomas.The clinical presentation of sarcoidosis after lymphoma treatment involves incidental mediastinal or hilar lymphadenopathy with no constitutional symptoms.The prognosis of sarcoidosis after lymphoma is generally mild. In our case, the six‐month follow‐up CT scan showed a marked decrease in mediastinal lymph node size. This is in agreement with a previous report in which only 41% of patients required treatment, whereas 36% of patients required oral corticosteroids; 91% of those patients showed a complete clinical response.In conclusion, we present a rare case of delayed‐onset sarcoidosis mimicking mediastinal lymphoma recurrence after CR of DLBCL. Because CT and PET scans are insufficient for a definitive diagnosis, pathological confirmation through biopsy is warranted when recurrence of lymphoma is suspected. An observational treatment strategy is reasonable in asymptomatic patients with normal pulmonary function tests.The authors declare that there are no conflicts of interest.