Photonically active bowtie nanoassemblies with chirality continuum.

Chirality is a geometrical property described by continuous mathematical functions1-5. However, in chemical disciplines, chirality is often treated as a binary left or right characteristic of molecules rather than a continuity of chiral shapes. Although they are theoretically possible, a family of stable chemical structures with similar shapes and progressively tuneable chirality is yet unknown. Here we show that nanostructured microparticles with an anisotropic bowtie shape display chirality continuum and can be made with widely tuneable twist angle, pitch, width, thickness and length. The self-limited assembly of the bowties enables high synthetic reproducibility, size monodispersity and computational predictability of their geometries for different assembly conditions6. The bowtie nanoassemblies show several strong circular dichroism peaks originating from absorptive and scattering phenomena. Unlike classical chiral molecules, these particles show a continuum of chirality measures2 that correlate exponentially with the spectral positions of the circular dichroism peaks. Bowtie particles with variable polarization rotation were used to print photonically active metasurfaces with spectrally tuneable positive or negative polarization signatures for light detection and ranging (LIDAR) devices.

Discovery of chalcogenides structures and compositions using mixed fluxes.

Advancements in many modern technologies rely on the continuous need for materials discovery. However, the design of synthesis routes leading to new and targeted solid-state materials requires understanding of reactivity patterns1-3. Advances in synthesis science are necessary to increase efficiency and accelerate materials discovery4-10. We present a highly effective methodology for the rational discovery of materials using high-temperature solutions or fluxes having tunable solubility. This methodology facilitates product selection by projecting the free-energy landscape into real synthetic variables: temperature and flux ratio. We demonstrate the effectiveness of this technique by synthesizing compounds in the chalcogenide system of A(Ba)-Cu-Q(O) (Q = S or Se; A = Na, K or Rb) using mixed AOH/AX (A = Li, Na, K or Rb; X = Cl or I) fluxes. We present 30 unreported compounds or compositions, including more than ten unique structural types, by systematically varying the temperature and flux ratios without requiring changing the proportions of starting materials. Also, we found that the structural dimensionality of the compounds decreases with increasing reactant solubility and temperature. This methodology serves as an effective general strategy for the rational discovery of inorganic solids.

Compositionally complex doping for zero-strain zero-cobalt layered cathodes.

The high volatility of the price of cobalt and the geopolitical limitations of cobalt mining have made the elimination of Co a pressing need for the automotive industry1. Owing to their high energy density and low-cost advantages, high-Ni and low-Co or Co-free (zero-Co) layered cathodes have become the most promising cathodes for next-generation lithium-ion batteries2,3. However, current high-Ni cathode materials, without exception, suffer severely from their intrinsic thermal and chemo-mechanical instabilities and insufficient cycle life. Here, by using a new compositionally complex (high-entropy) doping strategy, we successfully fabricate a high-Ni, zero-Co layered cathode that has extremely high thermal and cycling stability. Combining X-ray diffraction, transmission electron microscopy and nanotomography, we find that the cathode exhibits nearly zero volumetric change over a wide electrochemical window, resulting in greatly reduced lattice defects and local strain-induced cracks. In-situ heating experiments reveal that the thermal stability of the new cathode is significantly improved, reaching the level of the ultra-stable NMC-532. Owing to the considerably increased thermal stability and the zero volumetric change, it exhibits greatly improved capacity retention. This work, by resolving the long-standing safety and stability concerns for high-Ni, zero-Co cathode materials, offers a commercially viable cathode for safe, long-life lithium-ion batteries and a universal strategy for suppressing strain and phase transformation in intercalation electrodes.

Self-terminating, heterogeneous solid-electrolyte interphase enables reversible Li-ether cointercalation in graphite anodes.

Ether solvents are suitable for formulating solid-electrolyte interphase (SEI)-less ion-solvent cointercalation electrolytes in graphite for Na-ion and K-ion batteries. However, ether-based electrolytes have been historically perceived to cause exfoliation of graphite and cell failure in Li-ion batteries. In this study, we develop strategies to achieve reversible Li-solvent cointercalation in graphite through combining appropriate Li salts and ether solvents. Specifically, we design 1M LiBF4 1,2-dimethoxyethane (G1), which enables natural graphite to deliver ~91% initial Coulombic efficiency and >88% capacity retention after 400 cycles. We captured the spatial distribution of LiF at various length scales and quantified its heterogeneity. The electrolyte shows self-terminated reactivity on graphite edge planes and results in a grainy, fluorinated pseudo-SEI. The molecular origin of the pseudo-SEI is elucidated by ab initio molecular dynamics (AIMD) simulations. The operando synchrotron analyses further demonstrate the reversible and monotonous phase transformation of cointercalated graphite. Our findings demonstrate the feasibility of Li cointercalation chemistry in graphite for extreme-condition batteries. The work also paves the foundation for understanding and modulating the interphase generated by ether electrolytes in a broad range of electrodes and batteries.

Regulating Li Nucleation and Growth Heterogeneities via Near-Surface Lithium-Ion Irrigation for Stable Anode-Less Lithium Metal Batteries.

The inhomogeneous nucleation and growth of Li dendrite combined with the spontaneous side reactions with the electrolytes dramatically challenge the stability and safety of Li metal anode (LMA). Despite tremendous endeavors, current success relies on the use of significant excess of Li to compensate the loss of active Li during cycling. Herein, a near-surface Li+ irrigation strategy is developed to regulate the inhomogeneous Li deposition behavior and suppress the consequent side reactions under limited Li excess condition. The conformal polypyrrole (PPy) coating layer on Cu surface via oxidative chemical vapor deposition technique can induce the migration of Li+ to the interregional space between PPy and Cu, creating a near-surface Li+-rich region to smooth diffusion of ion flux and uniform the deposition. Moreover, as evidenced by multiscale characterizations including synchrotron high-energy X-ray diffraction scanning, a robust N-rich solid-electrolyte interface (SEI) is formed on the PPy skeleton to effectively suppress the undesired SEI formation/dissolution process. Strikingly, stable Li metal cycling performance under a high areal capacity of 10 mAh cm-2 at 2.0 mA cm-2 with merely 0.5 × Li excess is achieved. The findings not only resolve the long-standing poor LMA stability/safety issues, but also deepen the mechanism understanding of Li deposition process.

Spectrum mapping technology based creation of a color-contrast reading environment to reach comfort and clarity.

Reading with a bit of yellowish or greenish paper, as compared to white paper, is thought to be more comfortable and friendly, and can help decrease eye fatigue to some degree. In this work, we try to map the light of different colors on a given paper within a region of interest to alter the colors presented by the paper and consequently influence the reading experience. We conducted an ergonomic experiment to study the comfort and clarity under consistent illuminance levels. We adopted 6 color series(red, yellow, green, cyan, blue, and magenta), 5 chroma levels(0, 10, 20, 30, 40), and 4 types of paper with the same hue(yellow) but different lightness(the white, light yellow, yellow, and dark yellow), and conducted pairwise selection experiments within each light color series. Results show that white and low chroma (≈10) color characteristics contribute to comfort, while higher chroma blue(30∼40) color benefits clarity. Referring to white, low chroma greenish and yellowish color characteristics are preferred in terms of comfort and clarity. This work proposes the spectrum mapping technology to endow the paper with new color effects and verifies that although spectrum compositions might differ, people's preferences and comfort perception are consistent with the same object color.

ETV6::ACSL6 translocation-driven super-enhancer activation leads to eosinophilia in acute lymphoblastic leukemia through IL-3 overexpression.

ETV6::ACSL6 represents a rare genetic aberration in hematopoietic neoplasms and is often associated with severe eosinophilia, which confers an unfavorable prognosis requiring additional anti-inflammatory treatment. However, since the translocation is unlikely to produce a fusion protein, the mechanism of ETV6::ACSL6 action remains unclear. Here, we performed multi-omics analyses of primary leukemia cells and patient-derived xenografts from an acute lymphoblastic leukemia (ALL) patient with ETV6::ACSL6 translocation. We identified a super-enhancer located within the ETV6 gene locus and revealed translocation and activation of the super-enhancer associated with the ETV6::ACSL6 fusion. The translocated super-enhancer exhibited intense interactions with genomic regions adjacent to and distal from the breakpoint at chromosomes 5 and 12, including genes coding inflammatory factors such as IL-3. This led to modulations in DNA methylation, histone modifications, and chromatin structures, triggering transcription of inflammatory factors leading to eosinophilia. Furthermore, the bromodomain and extraterminal domain (BET) inhibitor synergized with standard-of-care drugs for ALL, effectively reducing IL-3 expression and inhibiting ETV6::ACSL6 ALL growth in vitro and in vivo. Overall, our study revealed for the first time a cis-regulatory mechanism of super-enhancer translocation in ETV6::ACSL6 ALL, leading to ALL-accompanying clinical syndrome. These findings may stimulate novel treatment approaches for this challenging ALL subtype.

HIV self-testing adoption and post-test linkage to care among men who have sex with men in China: a nationwide cross-sectional survey.

BACKGROUND: HIV self-testing (HIVST) was recommended to improve HIV testing services. China initiated some of the first HIVST pilots in the world, providing a unique opportunity for implementation research. We aim to investigate HIVST adoption and its following linkage to care among Chinese men who have sex with men (MSM). METHODS: Data were collected using an online questionnaire distributed on major social media platforms in 2018, one year after HIVST was officially endorsed and allowed for sale. MSM who were at least 16 years old, assigned as male at birth, and ever tested for HIV were eligible. Primary outcome, adoption was defined as ever use of HIVST. Bivariate and multivariable logistic regressions were performed to explore the association between HIVST adoption and sociodemographic and behavioral factors. Linkage to care was also described via the following sequential events as indicators: (1) receiving result after recent test (2), seeking care from healthcare facility if test result was positive or indeterminate, and (3) delayed time before seeking care. RESULTS: A total of 540 participants were included with an average age of 27.4 ± 6.6. Most were never married (87.4%) and half completed college (52.2%). Overall, 75.2% had adopted HIVST. Self-test kits were commonly obtained from community-based organizations (54.4%) and from online (46.6%). HIVST adoption was positively associated with having college or higher education (OR = 1.66, 95%CI: 1.07-2.57), and negatively associated with age older than 30 (AOR = 0.52, 95%CI: 0.32-0.84). Adoption was not associated with other socio-demographic or behavioral factors. After receiving HIV-positive or indeterminate results, 25/25 of HIVST adopters sought care while 3 out of 7 (42.9%) non-adopters sought care (p < 0.001). Delays before seeking care were not significantly different between HIVST adopters compared to non-adopters (P = 0.366). CONCLUSION: Many MSM adopted HIVST shortly after its launch. Our findings suggested that HIVST linkage to care is promising among MSM in China. Integration of HIVST with other essential sexual health services is needed.

Ferroptosis inducers: A new frontier in cancer therapy.

Ferroptosis represents a non-apoptotic form of programmed cell death characterized by iron-dependent lipid peroxidation. This cell death modality not only facilitates the direct elimination of cancer cells, but also enhances their susceptibility to other pharmacological anti-cancer agents. The burgeoning interest in ferroptosis has been driven by a growing body of evidence that underscores the efficiency and minimal toxicity of ferroptosis inducers. Traditional inducers, such as erastin and RSL3 have shown substantial promise in clinical applications due to their potent therapeutic effects. Their significant potential of these inducers has spurred the development of a variety of small molecule ferroptosis inducers. These novel inducers boast an enhanced structural variety, improved metabolic stability, the capability to initiate ferroptosis without triggering apoptosis, making them well-suited for in vivo use. Despite these advancements, challenges still remain, particularly concerning the drug delivery, tumor specificity, and circulation duration of these small molecules in vivo. Addressing these challenges, contemporary research has pivoted towards innovative delivery systems tailored for ferroptosis inducers to facilitate precise, targeted, and synegestic therapeutic delivery. This review scrutinizes the latest progress in small molecule ferroptosis inducers and nano drug delivery systems geared towards ferroptosis sensitization. Furthermore, it delineated the prospective therapeutic advantages and the existing hurdles in the development of ferroptosis inducers for malignant tumor treatment.

Changing trends in Chlamydia and gonorrhea infections among female sex workers in Southern China: a surveillance data analysis spanning 2019 to 2022.

BACKGROUND: Female sex workers (FSW) are particularly vulnerable to chlamydia and gonorrhea infections. However, there were few studies that detail the evolving patterns of chlamydia and gonorrhea among Chinese FSW. Therefore, our study endeavors to assess the prevalence of chlamydia and gonorrhea epidemics within FSW, investigate their changing trends and scrutinize associated factors. METHODS: In 2019, China instituted a sentinel surveillance network focused on FSW in Guangdong Province. This network conducted an annual serial cross-sectional survey spanning from April to August. All analyses are predicated on surveillance data accumulated between 2019 and 2022. RESULTS: The prevalence of chlamydia increased from 10.1 to 12.3%, exhibiting an annual percentage shift of 6.8%. Conversely, the prevalence of gonorrhea dwindled from 2.0 to 1.3%, marking an annual percentage decline of 13.4% (P < 0.001). After adjusting for covariates, chlamydia exhibited associations with having household registration in other provinces (adjusted odds ratio (aOR = 0.55)), displaying symptoms of sexually transmitted infections (STIs) (aOR = 1.65) and infected with gonorrhea (aOR = 5.68). In parallel, gonorrhea demonstrated associations with providing oral sex to clients (aOR = 3.74), manifesting STIs symptoms (aOR = 4.27) and those infected with chlamydia (aOR = 5.43). CONCLUSIONS: Our observations underscore the imperative to implement a comprehensive intervention strategy concentrating on chlamydia, while simultaneously fortifying endeavors to expand the scope of gonorrhea prevention services.

Framework-Topology-Controlled Singlet Fission in Metal-Organic Frameworks.

Singlet fission (SF) has been explored as a viable route to improve photovoltaic performance by producing more excitons. Efficient SF is achieved through a high degree of interchromophoric coupling that facilitates electron superexchange to generate triplet pairs. However, strongly coupled chromophores often form excimers that can serve as an SF intermediate or a low-energy trap site. The succeeding decoherence process, however, requires an optimum electronic coupling to facilitate the isolation of triplet production from the initially prepared correlated triplet pair. Conformational flexibility and dielectric modulation can provide a means to tune the SF mechanism and efficiency by modulating the interchromophoric electronic interaction. Such a strategy cannot be easily adopted in densely stacked traditional organic solids. Here, we show that the assembly of the SF-active chromophores around well-defined pores of solution-stable metal-organic frameworks (MOFs) can be a great platform for a modular SF process. A series of three new MOFs, built out from 9,10-bis(ethynylenephenyl)anthracene-derived struts, show a topology-defined packing density and conformational flexibility of the anthracene core to dictate the SF mechanism. Various steady-state and transient spectroscopic data suggest that the initially prepared singlet population can prefer either an excimer-mediated SF or a direct SF (both through a virtual charge-transfer (CT) state). These solution-stable frameworks offer the tunability of the dielectric environment to facilitate the SF process by stabilizing the CT state. Given that MOFs are a great platform for various photophysical and photochemical developments, generating a large population of long-lived triplets can expand their utilities in various photon energy conversion schemes.

Expanding hepatitis C virus test uptake using self-testing among men who have sex with men in China: two parallel randomized controlled trials.

BACKGROUND: HCV self-testing (HCVST) may be an effective strategy to address low rates of HCV test uptake among men who have sex with men (MSM). We evaluated the effectiveness and cost of providing HCVST to increase HCV test uptake among MSM in China. METHODS: Two parallel, unmasked, individual-level randomized controlled trials were conducted. HIV-negative MSM and MSM living with HIV were enrolled from 22 cities in China. Men in both trials were randomly assigned (1:1) into standard-of-care (SOC) or HCVST arms. The primary outcome was the proportion of participants who tested for HCV during the trial period. Intervention effects were estimated using multiply imputed data in the main analysis. Costs were measured using a micro-costing approach. RESULTS: A total of 84 men who were HIV-negative (trial 1) and 84 men living with HIV were enrolled (trial 2). Overall, the proportion of individuals who underwent HCV testing during the trial period was higher in the HCVST arm compared to SOC in trial 1 (estimated risk difference (RD): 71.1%, 95% CI: 54.6 to 87.7%) and trial 2 (estimated RD: 62.9%, 95% CI: 45.7 to 80.1%). Over half (58.6%, 34/58) of HCV self-testers reported the self-test was their first HCV test. The cost per person tested in trial 1 was $654.52 for SOC and $49.83 for HCVST, and in trial 2 was $438.67 for SOC and $53.33 for HCVST. CONCLUSIONS: Compared to the standard of care, providing HCVST significantly increased the proportion of MSM testing for HCV in China, and was cheaper per person tested. TRIAL REGISTRATION: Chinese Clinical Trial Registry. REGISTRATION NUMBER: ChiCTR2100048379.

Electrochemically Dealloyed 3D Porous Copper Nanostructure as Anode Current Collector of Li-Metal Batteries.

The commercialization of high-energy Li-metal batteries is impeded by Li dendrites formed during electrochemical cycling and the safety hazards it causes. Here, a novel porous copper current collector that can effectively mitigate the dendritic growth of Li is reported. This porous Cu foil is fabricated via a simple two-step electrochemical process, where Cu-Zn alloy is electrodeposited on commercial copper foil and then Zn is electrochemically dissolved to form a 3D porous structure of Cu. The 3D porous Cu layers on average have a thickness of ≈14 um and porosity of ≈72%. This current collector can effectively suppress Li dendrites in cells cycled with a high areal capacity of 10 mAh cm-2 and under a high current density of 10 mA cm-2 . This electrochemical fabrication method is facile and scalable for mass production. Results of advanced in situ synchrotron X-ray diffraction reveal the phase evolution of the electrochemical deposition and dealloying processes.

Artifact identification in X-ray diffraction data using machine learning methods.

In situ synchrotron high-energy X-ray powder diffraction (XRD) is highly utilized by researchers to analyze the crystallographic structures of materials in functional devices (e.g. battery materials) or in complex sample environments (e.g. diamond anvil cells or syntheses reactors). An atomic structure of a material can be identified by its diffraction pattern along with a detailed analysis of the Rietveld refinement which yields rich information on the structure and the material, such as crystallite size, microstrain and defects. For in situ experiments, a series of XRD images is usually collected on the same sample under different conditions (e.g. adiabatic conditions) yielding different states of matter, or is simply collected continuously as a function of time to track the change of a sample during a chemical or physical process. In situ experiments are usually performed with area detectors and collect images composed of diffraction patterns. For an ideal powder, the diffraction pattern should be a series of concentric Debye-Scherrer rings with evenly distributed intensities in each ring. For a realistic sample, one may observe different characteristics other than the typical ring pattern, such as textures or preferred orientations and single-crystal diffraction spots. Textures or preferred orientations usually have several parts of a ring that are more intense than the rest, whereas single-crystal diffraction spots are localized intense spots owing to diffraction of large crystals, typically >10 µm. In this work, an investigation of machine learning methods is presented for fast and reliable identification and separation of the single-crystal diffraction spots in XRD images. The exclusion of artifacts during an XRD image integration process allows a precise analysis of the powder diffraction rings of interest. When it is trained with small subsets of highly diverse datasets, the gradient boosting method can consistently produce high-accuracy results. The method dramatically decreases the amount of time spent identifying and separating single-crystal diffraction spots in comparison with the conventional method.

In situ X-ray area detector flat-field correction at an operating photon energy without flat illumination. Corrigendum.

The name of an author in the article by Weng et al. (2023) [J. Synchrotron Rad. 30, 546-554] is corrected.

In situ X-ray area detector flat-field correction at an operating photon energy without flat illumination.

Flat-field calibration of X-ray area detectors is a challenge due to the inability to generate an X-ray flat-field at the selected photon energy the beamline operates at, which has a strong influence on the measurement behavior of the detector. A method is presented in which a simulated flat-field correction is calculated without flat-field measurements. Instead, a series of quick scattering measurements from an amorphous scatterer is used to calculate a flat-field response. The ability to rapidly obtain a flat-field response allows for recalibration of an X-ray detector as needed without significant expenditure of either time or effort. Area detectors on the beamlines used, such as the Pilatus 2M CdTe, PE XRD1621 and Varex XRD 4343CT, were found to have detector responses that drift slightly over timescales of several weeks or after exposure to high photon flux, suggesting the need to more frequently recalibrate with a new flat-field correction map.

Does the smartphone's eye protection mode work?

People spend about 5-8 hours per day on phones, causing circadian disruption and eye fatigue, thus raising a great need for comfort and health. Most phones have eye protection modes, claiming a potential eye protection effect. To examine the effectiveness, we investigated the color quality, namely gamut area and just noticeable color difference (JNCD), and circadian effect, namely equivalent melanopic lux (EML) and melanopic daylight efficacy ratio (MDER), characteristics of two smartphones: iPhone 13 and HUAWEI P30, in normal and eye protection mode. The results show that the circadian effect is inversely proportional to color quality when the iPhone 13 and HUAWEI P30 changed from normal to eye protection mode. The gamut area changed from 102.51% to 82.5% sRGB and 100.36% to 84.55% sRGB, respectively. The EML and MDER decreased by 13 and 15, and, 0.50 and 0.38, respectively, affected by the eye protection mode and screen luminance. The EML and JNCD results in different modes show that the eye protection mode benefits the nighttime circadian effect at the cost of the image quality. This study provides a way to precisely assess the image quality and circadian effect of displays and elucidates the tradeoff relationship between them.

Observation of Traveling Breathers and Their Scattering in a Two-Fluid System.

The observation of traveling breathers (TBs) with large-amplitude oscillatory tails realizes an almost 50-year-old theoretical prediction [E. A. Kuznetsov and A. V. Mikhailov, Stability of stationary waves in nonlinear weakly dispersive media, Zh. Eksp. Teor. Fiz. 67, 1717 (1974) ZETFA70044-4510[E. A. Kuznetsov and A. V. MikhailovSov. Phys. JETP 40, 855 (1975)] SPHJAR0038-5646] and generalizes the notion of a breather. Two strongly nonlinear TB families are created in a core-annular flow by interacting a soliton and a nonlinear periodic (cnoidal) carrier. Bright and dark TBs are observed to move faster or slower, respectively, than the carrier while imparting a phase shift. Agreement with model equations is achieved. Scattering of the TBs is observed to be physically elastic. The observed TBs generalize to many continuum and discrete systems.

HCV knowledge and attitudes among HIV-negative MSM and MSM living with HIV in China: results from a cross-sectional online survey.

BACKGROUND: Men who have sex with men (MSM) are at high risk of hepatitis C virus (HCV) infection, especially for those living with human immunodeficiency virus (HIV). Learning about knowledge of and attitudes towards HCV is essential to inform health promotion interventions development. This is one of very limited studies to examine the level of knowledge and attitudes towards HCV and their determinants among HIV-negative MSM and MSM living with HIV in China. METHODS: A cross-sectional survey was conducted across seven provinces in China from December 2021 to January 2022. All the MSM living with HIV were recruited offline, whereas the recruitment ratio for HIV-negative MSM was half online and half offline. Data on socio-demographic characteristics, sexual behaviors, knowledge about HCV, and attitude towards HCV from participants were collected through the online survey. Univariate and multivariable logistic regressions were used to determine the associated factors. RESULTS: Only 39.3% (33/84) of HIV-negative men and 44.0% (37/84) of men living with HIV had a good level knowledge about HCV. Nearly one-third (32.1%, 27/84) of HIV-negative men and 41.7% (35/84) of men living with HIV reported a positive attitude towards HCV. For HIV-negative men, positive attitude towards HCV was associated with the multiple sexual partners (aOR: 5.8, 95%CI:1.9-18.1) and the use of recreational substances (aOR: 3.1, 95%CI: 1.0-9.4). For men living with HIV, knowledge about HCV was associated with disclosing sexual orientation to healthcare providers, family or friends (aOR: 7.0, 1.9-26.0), the multiple sexual partners (aOR: 0.2, 0.1-1.0), the use of recreational substances (aOR: 3.7, 95%CI: 1.1-13.1) and the HBV testing history (aOR: 7.3, 95%CI: 1.6-32.7); positive attitude towards HCV was associated with the use of recreational substances (aOR: 3.1, 95%CI: 1.1-9.0). CONCLUSIONS: The majority of Chinese MSM showed an inadequate knowledge of and negative attitude towards HCV irrespective of HIV infection status. More tailored education campaigns and multicomponent interventions are required to be targeted on MSM, and more researches are also needed to inform how best to address the negative attitudes of this population towards HCV.

Online commercial sex-seeking among female sex workers in south China: a cross-sectional study.

BACKGROUND: Online communication platforms have the potential to facilitate commercial sex among female sex workers (FSW), increasing the risk of contracting sexually transmitted diseases (STD). This study aimed to describe the patterns of online commercial sex-seeking and examine the associated factors among FSW in China. METHODS: A venue-based cross-sectional study was conducted in five cities in Guangdong Province, China, between April and October 2020. Data on socio-demographic characteristics, sexual behaviors, and online commercial sex-seeking patterns were collected through face-to-face interviews. Venous blood and urine samples were collected for STD testing. Univariate and multivariable logistic regressions were used to explore the factors associated with online commercial sex-seeking. RESULTS: A total of 1155 FSW were recruited in physical venues for this study. Among them, 33.42% reported ever using online applications to seek commercial sex. The prevalence of HIV, syphilis, gonorrhea, chlamydia, and STD was 0.26%, 1.30%, 4.40%, 15.54%, and 18.39%, respectively, among FSW who had ever used both physical and online venues to seek commercial sex, which was higher than among FSW who had never sought commercial sex online. Multivariable logistic regression indicated that FSW who used online platforms to seek commercial sex were more likely to have STD (adjusted odds ratio (aOR) = 1.48, 95%CI: 1.05-2.09), experience unintended pregnancies due to commercial sex (aOR = 1.78, 95%CI: 1.21-2.62), be diagnosed as infertile (aOR = 3.20, 95%CI: 1.42-7.21), and undergo abortions (aOR = 1.69, 95%CI: 1.29-2.20). CONCLUSION: A significant proportion of FSW who practiced in physical venues in China engaged in seeking commercial sex online, and this behavior is positively correlated with both STD and reproductive health outcomes. Given the high prevalence of online sex-seeking, it is crucial to provide a wide range of internet-based healthcare interventions and reproductive health services to Chinese FSW.