What Is the Magical Cavitation Bubble: A Holistic Perspective to Trigger Advanced Bubbles, Nano-Sonocatalysts, and Cellular Sonosensitizers.

Sonodynamic therapy (SDT) has emerged as a novel and highly researched advancement in the medical field. Traditional ultrasound contrast agents and novel bubble-shaped agents are used to stimulate cavitation and enhance SDT efficiency. However, the impact of artificially modified shell structures on the acoustic properties of microbubbles remains to be explored. Alternatively, in the absence of bubble-shaped agents, some clinically available organic sonosensitizers and advanced inorganic materials are also used to enhance the efficacy of SDT. Diagnostic and therapeutic ultrasound can also activate cavitation bubbles, which supply energy to sonosensitive agents, leading to the production of cytotoxic free radicals to achieve therapeutic effects. While inorganic materials often spark controversy in clinical applications, their relatively simple structure enables researchers to gain insight into the mechanism by which SDT produces various free radicals. Some organic-inorganic hybrid sonosensitive systems have also been reported, combining the benefits of inorganic and organic sonosensitive agents. Alternatively, by employing cell surface modification engineering to enable cells to perform functions such as immune escape, drug loading, gas loading, and sonosensitivity, cellular sonosensitizers have also been developed. However, further exploration is needed on the acoustic properties, ability to generate reactive oxygen species (ROS), and potential clinical application of this cellular sonosensitizer. This review offers a comprehensive analysis of vesical microbubbles and nanoscale sonocatalysts, including organic, inorganic, combined organic-inorganic sonosensitizers, and cellular sonosensitizers. This analysis will enhance our understanding of SDT and demonstrate its important potential in transforming medical applications.

A primary wideband calibration method for noise hydrophones based on three-transducer spherical wave reciprocity in the frequency domain.

A primary wideband calibration method for noise hydrophones is developed, which can be applied to obtain noise acoustic spectral density sensitivity in the free-field. In this method, a wideband three-transducer spherical wave reciprocity calibration method is proposed in the frequency domain. A lowpass spatial domain filter is utilized to eliminate the reflecting acoustic waves from boundaries and water surface, and the wideband frequency responses of the transducer pair are calculated. Wideband calibrations are performed in a laboratory anechoic water tank, and two hydrophones with different reference sensitivities are calibrated in the frequency range of 250 Hz to 20 kHz using noise signals. The decidecade band sensitivities are obtained by the primary wideband calibration, which is in agreement with the single frequency sensitivities. The expended uncertainty of the primary wideband calibration is analyzed and estimated to be 8.9% (k = 2).

Steerable ultrasonic propulsion of rigid objects based on circular pressure modulation of a focused sectorial transducer array.

As a common disease of human urinary system, the high prevalence and incidence rate of renal calculus have brought heavy burden to society. Traditional ultrasonic lithotripsy struggles with the comprehensive elimination of residual fragments and may inadvertently inflict renal damage. Although focused ultrasound can propel stones by the acoustic radiation force (ARF) with minimal tissue damage and enhanced passage rate, it is still lack of the accurate control for calculi at different locations. A circular pressure modulation approach for steerable ultrasonic propulsion of rigid objects is developed based on a sector-array of focused transducers. The ARF exerted on on-axis rigid spheres (stones) is derived based on acoustic scattering. It is proved that the ARF of focused fields exhibits an axial distribution of increasing followed by decreasing with the peak slightly beyond the focus. As the sphere radius increases, the ARF exerted on spheres at the focus increases accordingly with a decreasing growth rate. Inclined propulsion can be realized by the circular binary pressure modulation with the deflection increased by expanding the angle of power-off sector sources. The maximum deflection angle approaching 60° is determined by the F-number and element number of the sector-array. Experimental propulsions of steel balls are conducted using an 8-element sector-array with motion trajectories captured by a high-speed camera. Distributions of the motion speed and acceleration for steel balls of different radii are calculated through image processing. The ARF of mN level and the deflection angle of 12° are demonstrated by the successful propulsion of steel balls. This research provides an effective and flexible approach of steerable stone propulsion using an ultrasonic power supply without the complex control in amplitude or phase and the high-precision motion of the sector-array, hence promoting the practical application in non-invasive treatment of stones.

Near-infrared and ultrasound triggered Pt/Pd-engineered cluster bombs for the treatment of solid tumors.

Owing to the dense extracellular matrix and high interstitial fluid pressure in the tumor microenvironment, methods which enhance the permeation and retention of nano drugs into liver tumors remain unsatisfactory for successful tumor treatment. We designed a near-infrared (NIR)- and ultrasound (US)-triggered Pt/Pd-engineered "cluster bomb" (Pt/Pd-CB) which actively penetrates liver cancer cell membranes and achieves photothermal and sonodynamic therapy (SDT). The physical forces generated by the fast expansion and collapse of perfluoropentane nanodroplets eject "sub bombs" (Pt/Pd nanoalloys) into liver cancer cells upon activation by NIR and US. Pt/Pd nanoalloys can then convert H2O2 into O2 to alleviate hypoxia and boost SDT efficiency while exhibiting a highly efficient photothermal response under NIR irradiation. Our findings might especially be promising for the treatment of solid tumors.

[Early identification of acute kidney injury in children with primary nephrotic syndrome]. / å„¿ç«¥åŽŸå‘æ€§è‚¾ç— ç»¼åˆå¾å¹¶å‘æ€¥æ€§è‚¾æŸä¼¤çš„æ—©æœŸè¯†åˆ«.

OBJECTIVES: To investigate the incidence and risk factors for acute kidney injury (AKI) in children with primary nephrotic syndrome (PNS), as well as the role of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in the early identification of AKI in these children. METHODS: A prospective collection of clinical data from children hospitalized with PNS at the Children's Hospital of the Capital Institute of Pediatrics from January 2021 to October 2022 was conducted. The children were divided into two groups based on the presence of AKI: the AKI group (47 cases) and the non-AKI group (169 cases). The risk factors for AKI in children with PNS were identified by multivariate logistic regression analysis. Urinary KIM-1 and NGAL levels were compared between the AKI and non-AKI groups, as well as among the different stages of AKI. RESULTS: The incidence of AKI in children with PNS was 21.8%. Multivariate logistic regression analysis revealed that steroid-resistant nephrotic syndrome, gastrointestinal infections, and heavy proteinuria were independent risk factors for AKI in these children with PNS (P<0.05). Urinary KIM-1 and NGAL levels were higher in the AKI group compared to the non-AKI group (P<0.05), and the urinary NGAL and KIM-1 levels in the AKI stage 2 and stage 3 subgroups were higher than those in the AKI stage 1 subgroup (P<0.017). CONCLUSIONS: KIM-1 and NGAL can serve as biomarkers for the early diagnosis of AKI in children with PNS. Identifying high-risk populations for AKI in children with PNS and strengthening the monitoring of related risk factors is of significant importance.

2D spatiotemporal passive cavitation imaging and evaluation during ultrasound thrombolysis based on diagnostic ultrasound platform.

Acoustic cavitation plays a critical role in various biomedical applications. However, uncontrolled cavitation can lead to undesired damage to healthy tissues. Therefore, real-time monitoring and quantitative evaluation of cavitation dynamics is essential for understanding underlying mechanisms and optimizing ultrasound treatment efficiency and safety. The current research addressed the limitations of traditionally used cavitation detection methods by developing introduced an adaptive time-division multiplexing passive cavitation imaging (PCI) system integrated into a commercial diagnostic ultrasound platform. This new method combined real-time cavitation monitoring with B-mode imaging, allowing for simultaneous visualization of treatment progress and 2D quantitative evaluation of cavitation dosage within targeted area. An improved delay-and-sum (DAS) algorithm, optimized with a minimum variance (MV) beamformer, is utilized to minimize the side lobe effect and improve the axial resolution typically associated with PCI. In additional to visualize and quantitatively assess the cavitation activities generated under varied acoustic pressures and microbubble concentrations, this system was specifically applied to perform 2D cavitation evaluation for ultrasound thrombolysis mediated by different solutions, e.g., saline, nanodiamond (ND) and nitrogen-annealed nanodiamond (N-AND). This research aims to bridge the gap between laboratory-based research systems and real-time spatiotemporal cavitation evaluation demands in practical uses. Results indicate that this improved 2D cavitation monitoring and evaluation system could offer a useful tool for comprehensive evaluating cavitation-mediated effects (e.g., ultrasound thrombolysis), providing valuable insights into in-depth understanding of cavitation mechanisms and optimization of cavitation applications.

Savior or saboteur? A nationwide study on digital economy and depression in China.

The regional boom in digital economy has provided people with remote conversations and socialization while reducing the risk of depression. This study aims to elucidate whether regional digital economy can be a savior for individual depression. The multi-source dataset collects 11,845 individuals from the China Health and Retirement Longitudinal Study 2018 (CHARLS), with the combination of corresponding regional data from China City Statistical Yearbooks. A series of regressions with integrated mediation and moderation analyses are employed to bridge the link between the digital economy and depression. The results suggest that people living in areas with a higher level of digital economy are less likely to suffer from depression. The development of the digital economy helps people find solace or air grievances more easily, thereby reducing the risk of depression. Individual information and communications technology (ICT) engagement is found to mediate the relationship between the regional digital economy and individual depression. Residence type moderates the association between the three casual pairs of digital economy, ICT engagement, and depression. Improved digitization stimulates personal engagement with ICTs, which in turn expands social connections and support. Strengthened social interactions naturally keep depression away. Moreover, the urban-rural differences further confirm the underlying mechanism. Properly embracing the new digital world can therefore benefit from the transformative potential and mitigate depressive outcomes.

Acute Focal Bacterial Nephritis without Pyuria: A Peculiar Subtype of Urinary Tract Infection.

Acute focal bacterial nephritis (AFBN) without pyuria is a subtype of urinary tract infection in children, often leading to diagnostic challenges. The clinical characteristics of 6 children diagnosed with AFBN, who exhibited an absence of pyuria, were retrospectively summarized and compared with the control group consisting of 49 hospitalized AFBN children with pyuria. The cases of AFBN without pyuria presented with more severe inflammatory responses and were predisposed to complications, such as sepsis and neurological abnormalities.

The U-shape Association between Population Agglomeration and Individual Depression: the Role of Dialect Diversity.

Depression is a relevant mental illness affecting hundreds of millions of people worldwide. As urbanization accelerates, agglomeration of populations has altered individual social network distances and life crowding, which in turn affects depressive prevalence. However, the association between depression and population agglomeration (PA) remains controversial. This study aims to explore whether and how PA could influence individual depression. Based on the China Health and Retirement Longitudinal Study (CHARLS) 2018, the empirical results showed that there was a U-shaped association between PA and individual CES-D scores. As PA increases, the risk of depression first decreases and then increases. CES-D was lowest at moderate aggregation. Dialect diversity (DD) was positively related to the incidence of individual depression. The higher the DD, the higher the risk of depression. Meanwhile, DD also played a moderating role in the association between PA and individual depression. Our observations suggest that the optimistic level of agglomeration for individual mental health is within 1500 to 2000 persons per square kilometer.

Real-time passive cavitation mapping and B-mode fusion imaging via hybrid adaptive beamformer with modified diagnostic ultrasound platform.

The implementation of real-time, convenient and high-resolution passive cavitation imaging (PCM) is crucial for ensuring the safety and effectiveness of ultrasound applications related to cavitation effects. However, the current B-mode ultrasound imaging system cannot achieve these functions. By developing a hybrid adaptive beamforming algorithm, the current work presented a real-time PCM and B-mode fusion imaging technique, using a modified diagnostic ultrasound platform enabling time-division multiplexing external triggering function. The proposed hybrid adaptive beamformer combined the advantages of delay-multiply-and-sum (DMAS) and minimum variance (MV) methods to effectively suppress the side lobe and tail-like artifacts, improving the resolution of PCM images. A high-pass filter was applied to selectively detect cavitation-specific signals while removing the interference from the tissue scatters. The system enabled synchronous visualization of tissue structure and cavitation activity under ultrasound exposure. Both numerical and experimental studies demonstrated that, compared with DAS, MV-DAS and DMAS methods, the proposed MV-DMAS algorithm performed better in both axial and lateral resolutions. This work represented a significant advancement in achieving high-quality real-time B-mode and PCM fusion imaging utilizing commercial medical ultrasound system, providing a powerful tool for synchronous monitoring and manipulating cavitation activity, which would enhance the safety and efficacy of cavitation-based applications.

Efficacy and safety of belimumab combined with the standard regimen in treating children with lupus nephritis.

The purpose of this study is to evaluate the efficacy and safety of belimumab combined with the standard regimen in treating children with active lupus nephritis. This single-center, retrospective cohort study used clinical data of children with newly active lupus nephritis hospitalized in the Department of Nephrology between December 2004 and February 2023. Patients were divided into a belimumab or traditional treatment group according to whether or not they received belimumab. Renal remission and recurrence rates and glucocorticoid dose were compared between groups. Forty-seven children (median age 11 years) were enrolled, including 30 and 17 children in the traditional treatment and belimumab groups, respectively. The Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2000) score of children in the belimumab group (23.59 ± 7.78) was higher than that in the traditional treatment group (19.13 ± 6.10) (P = 0.035). The two groups showed no significant difference in the frequency of pyuria, gross hematuria, and the levels of 24-h proteinuria and estimated glomerular filtration rate. The complement C3/C4 in the belimumab group recovered faster than that in the traditional treatment group (P < 0.05). There were no between-group differences in the complete renal remission rate at 6 or 12 months (P = 0.442, P = 0.759). There were no between-group differences in 1-year recurrence rate (P = 0.303). Furthermore, 6 and 12 months after treatment, glucocorticoid doses were lower in the belimumab than the traditional treatment group (17.87 ± 6.96 mg/d vs. 27.33 ± 8.40 mg/d, P = 0.000; 10.00 (5.3) mg/d vs. 13.75 (10.0) mg/d, P = 0.007), respectively. CONCLUSION: With an equivalent renal remission rate, belimumab combined with the standard traditional regimen might promote the tapering of glucocorticoids, and the incidence of adverse events is low. WHAT IS KNOWN: • Belimumab is documented as an adjunctive treatment with systemic lupus erythematosus (c-SLE) LN with efficacy. • Due to the paucity of studies, its effects and side effects in children with LN remain unclear. WHAT IS NEW: • This single-center, retrospective cohort study evaluated the efficacy and safety of belimumab combined with the standard regimen in treating children with proliferative LN. • Belimumab combined with the standard traditional treatment might promote the tapering of glucocorticoids, while exhibiting a low occurrence of adverse events.

SAP deletion promotes malignant insulinoma progression by inducing CXCL12 secretion from CAFs via the CXCR4/p38/ERK signalling pathway.

Malignant insulinoma is an extremely rare type of functioning pancreatic neuroendocrine tumour with a high degree of malignancy and a high incidence of metastasis. However, it is still unclear how malignant insulinomas develop and metastasize. Serum amyloid P component (SAP), a member of the pentraxin protein family, is an acute-phase protein secreted by liver cells. The role of SAP in insulinoma and the related mechanism are still unknown. To determine the effect of SAP on insulinoma, we crossed Rip1-Tag2 mice, which spontaneously develop insulinoma, and SAP knockout (KO) mice to generate Rip1-Tag2;SAP-/- mice. We found that SAP deletion significantly promoted the growth, invasion and metastasis of malignant insulinoma through C-X-C motif chemokine ligand 12 (CXCL12) secreted by cancer-associated fibroblasts (CAFs). Further study showed that SAP deletion promoted CXCL12 secretion by CAFs through the CXCR4/p38/ERK signalling pathway. These findings reveal a novel role and mechanism of SAP in malignant insulinoma and provide direct evidence that SAP may be a therapeutic agent for this disease.

A lung disease diagnosis algorithm based on 2D spectral features of ultrasound RF signals.

Lung diseases are commonly diagnosed based on clinical pathological indications criteria and radiological imaging tools (e.g., X-rays and CT). During a pandemic like COVID-19, the use of ultrasound imaging devices has broadened for emergency examinations by taking their unique advantages such as portability, real-time detection, easy operation and no radiation. This provides a rapid, safe, and cost-effective imaging modality for screening lung diseases. However, the current pulmonary ultrasound diagnosis mainly relies on the subjective assessments of sonographers, which has high requirements for the operator's professional ability and clinical experience. In this study, we proposed an objective and quantifiable algorithm for the diagnosis of lung diseases that utilizes two-dimensional (2D) spectral features of ultrasound radiofrequency (RF) signals. The ultrasound data samples consisted of a set of RF signal frames, which were collected by professional sonographers. In each case, a region of interest of uniform size was delineated along the pleural line. The standard deviation curve of the 2D spatial spectrum was calculated and smoothed. A linear fit was applied to the high-frequency segment of the processed data curve, and the slope of the fitted line was defined as the frequency spectrum standard deviation slope (FSSDS). Based on the current data, the method exhibited a superior diagnostic sensitivity of 98% and an accuracy of 91% for the identification of lung diseases. The area under the curve obtained by the current method exceeded the results obtained that interpreted by professional sonographers, which indicated that the current method could provide strong support for the clinical ultrasound diagnosis of lung diseases.

Depressive disorder benefits of cities: Evidence from the China.

BACKGROUND: Rapid urbanization is a major trend in global population migration. There is growing debate about whether this urban-rural disparity exacerbate depression at the individual level. This study aims to investigate how urban living has a beneficial impact on individual mental health. METHODS: Based on the data of 15,764 participants in the 2018 China Health and Retirement Longitudinal Study (CHARLS), we perform analysis of variance to identify the gap in depression levels between urban and rural areas. Extensive comparisons and detailed statistical analyses are carried out to demonstrate the differences in social participation between urban and rural residents. Finally, we conduct a series of mediation and moderation analyses to reveal the underlying mechanisms of depressive disorder benefits of cities. RESULTS: The results indicate that those who lived in urban areas were less likely to suffer from depression (ß = -1.461, 95 % CI = [-1.691, -1.235], p < 0.001). Social engagement is found to mediate the relationship between residence type (ß = 0.164, 95 % CI = [0.136, 0.193], p < 0.001) and individual depression (ß = -0.462, 95 % CI = [-0.587, -0.337], p < 0.001). City size plays a moderating role in the association between urban living and social engagement. LIMITATIONS: The mechanism is conducted through cross-sectional data. Self-reported depression status is accessed in this study, which could lead to measurement error. CONCLUSION: This study demonstrates the beneficial effects of urban living on individual depression, and reveals the mechanism by which urbanization at different scales affects the prevalence of depression.

Improved assessment sensitivity of time-varying cavitation events based on wavelet analysis.

Ultrasonic cavitation, characterized by the oscillation or abrupt collapse of cavitation nuclei in response to ultrasound stimulation, plays a significant role in various applications within both industrial and biomedical sectors. In particular, inertial cavitation (IC) has garnered considerable attention due to the resulting mechanical, chemical, and thermal effects. Passive cavitation detection (PCD) has emerged as a valuable technique for monitoring this procedure. While the fast Fourier transform (FFT) is a widely used algorithm to analyze IC-induced broadband noise detected by PCD system, it may not adequately capture the time-varying instability of cavitation due to potential nuclei collapse during ultrasound irradiation. In contrast, the continuous wavelet transform offers a more flexible approach, enabling more sensitive analysis of signals with varying frequencies over time. In this study, nanodiamond (ND) and its derivative, nitro-doped nanodiamond (N-AND), known to possess cavitation potential from previous research, were chosen as the source of cavitation nuclei. The cavitation signals detected by PCD were subjected to both FFT and wavelet analyses, with their results comprehensively compared. This research showcased the feasibility of employing wavelet analysis for effective inertial cavitation evaluation. It provided the advantage of monitoring the temporal evolution of cavitation events in real-time, enhancing sensitivity to weak and unstable cavitation signals, especially those in higher order components (3rd and 4th order). Additionally, it yielded a higher level of precision in determining IC thresholds and doses. Furthermore, the inclusion of time information through wavelet analysis offered insights into the limitations of low-cycle ultrasound in inducing IC. This study introduces a novel perspective for more sensitive and precise cavitation assessment, leveraging time and frequency data from wavelet analysis, and holds promise for effective utilization of cavitation effects while minimizing losses and damages resulting from unintended cavitation events.

Long-Term Indomethacin Treatment in a Chinese Child with Gitelman Syndrome: Case Report and Literature Review on its Efficacy and Tolerance.

BACKGROUND Gitelman syndrome (GS) is a rare inherited autosomal recessive salt-losing renal tubulopathy. Early-onset GS is difficult to differentiate from Bartter syndrome (BS). It has been reported in some cases that cyclooxygenase (COX) inhibitors, which pharmacologically reduce prostaglandin E2(PGE2) synthesis, are helpful for GS patients, especially in children, but the long-term therapeutic effect has not yet been revealed. CASE REPORT A 4-year-old boy was first brought to our hospital for the chief concern of short stature and growth retardation. Biochemical tests demonstrated severe hypokalemia, hyponatremia, and hypochloremic metabolic alkalosis. The patient's serum magnesium was normal. He was diagnosed with BS and treated with potassium supplementation and indomethacin and achieved stable serum potassium levels and slow catch-up growth. At 11.8 years of age, the patient showed hypomagnesemia and a genetic test confirmed that he had GS with compound heterozygous mutations in the SLC12A3 gene. At the age of 14.8 years, when indomethacin had been taken for nearly 10 years, the boy reported having chronic stomachache, while his renal function remained normal. After proton pump inhibitor and acid inhibitor therapy, the patient's symptoms were ameliorated, and he continued to take a low dose of indomethacin (37.5 mg/d divided tid) with good tolerance. CONCLUSIONS Early-onset GS in childhood can be initially misdiagnosed as BS, and gene detection can confirm the final diagnosis. COX inhibitors, such as indomethacin, might be tolerated by pediatric patients, and long-term therapy can improve the hypokalemia and growth retardation without significant adverse effects.

[Therapeutic effect of mycophenolate mofetil or cyclophosphamide in children with Henoch-Schönlein purpura nephritis of different age groups]. / ä¸åŒå¹´é¾„æ®µè¿‡æ•æ€§ç´«ç™œæ€§è‚¾ç‚Žæ‚£å„¿æŽ¥å—éœ‰é šé ¸é ¯æˆ–çŽ¯ç£·é °èƒºæ²»ç–—çš„ç–—æ•ˆå·®å¼‚åˆ†æž.

OBJECTIVES: To investigate the difference in the therapeutic effect of mycophenolate mofetil (MMF) or cyclophosphamide (CTX) in children with Henoch-Schönlein purpura nephritis (HSPN) of different age groups. METHODS: A retrospective analysis was conducted on the clinical data of 135 children with HSPN who were treated with MMF or CTX in the Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics, from October 2018 to October 2020. According to the immunosuppressant used, they were divided into two groups: MMF group and CTX group, and according to the age, each group was further divided into two subgroups: ≤12 years and >12 years, producing four groups, i.e, the ≤12 years MMF subgroup (n=30), the >12 years MMF subgroup (n=15), the ≤12 years CTX subgroup (n=71), and the >12 years CTX subgroup (n=19). All children were followed up for at least 12 months, and the above groups were compared in terms of clinical outcomes and the incidence rate of adverse reactions. RESULTS: There was no significant difference in the complete response rate between the MMF group and the CTX group after 3, 6, and 12 months of treatment (P>0.05). There were no significant difference in the complete response rate and the incidence rate of adverse reactions between the >12 years MMF subgroup and the ≤12 years MMF subgroup at 3, 6, and 12 months of treatment (P>0.05). The >12 years CTX subgroup had a significantly lower complete response rate than the ≤12 years CTX subgroup at 6 and 12 months of treatment (P<0.05). The >12 years CTX subgroup had a significantly higher incidence rate of adverse reactions than the >12 years MMF subgroup (P<0.05). CONCLUSIONS: The efficacy and adverse reactions of MMF are not associated with age, but the efficacy of CTX is affected by age, with a higher incidence rate of adverse reactions. CTX should be selected with caution for children with HSPN aged >12 years.

Depression prediction based on LassoNet-RNN model: A longitudinal study.

Depression has become a widespread health concern today. Understanding the influencing factors can promote human mental health as well as provide a basis for exploring preventive measures. Combining LassoNet with recurrent neural network (RNN), this study constructed a screening model ,LassoNet-RNN, for identifying influencing factors of individual depression. Based on multi-wave surveys of China Health and Retirement Longitudinal Study (CHARLS) dataset (11,661 observations), we analyzed the multivariate time series data and recognized 27 characteristic variables selected from four perspectives: demographics, health-related risk factors, household economic status, and living environment. Additionally, the importance rankings of the characteristic variables were obtained. These results offered insightful recommendations for theoretical developments and practical decision making in public health.

Infodemic: Challenges and solutions in topic discovery and data process.

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) pandemic was a huge shock to society, and the ensuing information problems had a huge impact on society at the same time. The urgent need to understand the Infodemic, i.e., the importance of the spread of false information related to the epidemic, has been highlighted. However, while there is a growing interest in this phenomenon, studies on the topic discovery, data collection, and data preparation phases of the information analysis process have been lacking. OBJECTIVE: Since the epidemic is unprecedented and has not ended to this day, we aimed to examine the existing Infodemic-related literature from January 2019 to December 2022. METHODS: We have systematically searched ScienceDirect and IEEE Xplore databases with some search limitations. From the searched literature we selected titles, abstracts and keywords, and limitations sections. We conducted an extensive structured literature search and analysis by filtering the literature and sorting out the available information. RESULTS: A total of 47 papers ended up meeting the requirements of this review. Researchers in all of these literatures encountered different challenges, most of which were focused on the data collection step, with few challenges encountered in the data preparation phase and almost none in the topic discovery section. The challenges were mainly divided into the points of how to collect data quickly, how to get the required data samples, how to filter the data, what to do if the data set is too small, how to pick the right classifier and how to deal with topic drift and diversity. In addition, researchers have proposed partial solutions to the challenges, and we have also proposed possible solutions. CONCLUSIONS: This review found that Infodemic is a rapidly growing research area that attracts the interest of researchers from different disciplines. The number of studies in this field has increased significantly in recent years, with researchers from different countries, including the United States, India, and China. Infodemic topic discovery, data collection, and data preparation are not easy, and each step faces different challenges. While there is some research in this emerging field, there are still many challenges that need to be addressed. These findings highlight the need for more articles to address these issues and fill these gaps.