An Investigation of Quorum Sensing Inhibitors against Bacillus cereus in The Endophytic Fungus Pithomyces sacchari of the Laurencia sp.

Bacillus cereus, a common food-borne pathogen, forms biofilms and generates virulence factors through a quorum sensing (QS) mechanism. In this study, six compounds (dankasterone A, demethylincisterol A3, zinnimidine, cyclo-(L-Val-L-Pro), cyclo-(L-Ile-L-Pro), and cyclo-(L-Leu-L-Pro)) were isolated from the endophytic fungus Pithomyces sacchari of the Laurencia sp. in the South China Sea. Among them, demethylincisterol A3, a sterol derivative, exhibited strong QS inhibitory activity against B. cereus. The QS inhibitory activity of demethylincisterol A3 was evaluated through experiments. The minimum inhibitory concentration (MIC) of demethylincisterol A3 against B. cereus was 6.25 µg/mL. At sub-MIC concentrations, it significantly decreased biofilm formation, hindered mobility, and diminished the production of protease and hemolysin activity. Moreover, RT-qPCR results demonstrated that demethylincisterol A3 markedly inhibited the expression of QS-related genes (plcR and papR) in B. cereus. The exposure to demethylincisterol A3 resulted in the downregulation of genes (comER, tasA, rpoN, sinR, codY, nheA, hblD, and cytK) associated with biofilm formation, mobility, and virulence factors. Hence, demethylincisterol A3 is a potentially effective compound in the pipeline of innovative antimicrobial therapies.

Development of a Large-Range XY-Compliant Micropositioning Stage with Laser-Based Sensing and Active Disturbance Rejection Control.

This paper presents a novel design and control strategies for a parallel two degrees-of-freedom (DOF) flexure-based micropositioning stage for large-range manipulation applications. The motion-guiding beam utilizes a compound hybrid compliant prismatic joint (CHCPJ) composed of corrugated and leaf flexures, ensuring increased compliance in primary directions and optimal stress distribution with minimal longitudinal length. Additionally, a four-beam parallelogram compliant prismatic joint (4BPCPJ) is used to improve the motion decoupling performance by increasing the off-axis to primary stiffness ratio. The mechanism's output compliance and dynamic characteristics are analyzed using the compliance matrix method and Lagrange approach, respectively. The accuracy of the analysis is verified through finite element analysis (FEA) simulation. In order to examine the mechanism performance, a laser interferometer-based experimental setup is established. In addition, a linear active disturbance rejection control (LADRC) is developed to enhance the motion quality. Experimental results illustrate that the mechanism has the capability to provide a range of 2.5 mm and a resolution of 0.4 µm in both the X and Y axes. Furthermore, the developed stage has improved trajectory tracking and disturbance rejection capabilities.

Hepatitis B virus infection in patients with Wilson disease: A large retrospective study.

BACKGROUND: Wilson disease (WD) is the most common genetic metabolic liver disease. Some studies have shown that comorbidities may have important effects on WD. Data on hepatitis B virus (HBV) infection in patients with WD are limited. AIM: To investigate the prevalence and clinical impact of HBV infection in patients with WD. METHODS: The clinical data of patients with WD were analyzed retrospectively, and the data of patients with concurrent WD and HBV infection were compared with those of patients with isolated WD. RESULTS: Among a total of 915 WD patients recruited, the total prevalence of current and previous HBV infection was 2.1% [95% confidence interval (CI): 1.2%-3.0%] and 9.2% (95%CI: 7.3%-11.1%), respectively. The main finding of this study was the identification of 19 patients with concurrent WD and chronic hepatitis B (CHB) infection. The diagnosis of WD was missed in all but two patients with CHB infection. The mean delay in the diagnosis of WD in patients with concurrent WD and CHB infection was 32.5 mo, which was significantly longer than that in patients with isolated WD (10.5 mo). The rates of severe liver disease and mortality in patients with concurrent WD and CHB infection were significantly higher than those in patients with isolated WD (63.1% vs 19.3%, P = 0.000 and 36.8% vs 4.1%, P < 0.001, respectively). Binary logistic regression analysis revealed a significantly higher risk of severe liver disease at the diagnosis of WD in patients with current HBV infection [odds ratio (OR) = 7.748; 95%CI: 2.890-20.774; P = 0.000)] or previous HBV infection (OR = 5.525; 95%CI: 3.159-8.739; P = 0.000) than in patients with isolated WD. CONCLUSION: The total prevalence of current HBV infection in patients with WD was 2.1%. The diagnosis of WD in CHB patients is usually missed. HBV infection is an independent risk factor for severe liver disease in WD patients. The diagnosis of WD should be ruled out in some patients with CHB infection.

Facile Entry to Pharmaceutically Important 3-Difluoromethyl-quinoxalin-2-ones Enabled by Visible-Light-Driven Difluoromethylation of Quinoxalin-2-ones.

CF2H moiety has a significant potential utility in drug design and discovery, and the incorporation of CF2H into biologically active molecules represents an important and efficient strategy for seeking lead compounds and drug candidates. On the other hand, quinoxalin-2-one is of great interest to pharmaceutical chemists as a common skeleton frequently occurring in plenty of natural products and bioactive compounds. Herein, we reported a practical and efficient protocol for the synthesis of 3-CF2H-quinoxalin-2-ones. Thus, in the presence of 3 mol% of photocatalyst and S-(difluoromethyl)sulfonium salt as difluoromethyl radical sources, a wide range of quinoxalin-2-ones readily underwent a visible-light redox-catalyzed difluoromethylation reaction, to deliver structurally diverse 3-difluoromethyl-quinoxalin-2-ones. We believe that this would facilitate increasing chances and possibilities for seeking potential lead compounds and drug candidates and further boost the development of fluorine-containing pharmaceuticals.

Application value of endoscopic retrograde biliary drainage for acute obstructive suppurative cholangitis in the elderly / 中华消化内镜杂志

Objective:To evaluate the safety and efficacy of endoscopic retrograde biliary drainage (ERBD) for acute obstructive suppurative cholangitis (AOSC) in the elderly.Methods:A retrospective analysis was performed on the clinical data of AOSC patients admitted to the First Affiliated Hospital of Xinjiang Medical University from January 2018 to January 2020. Patients aged 75 years and over ( n=49) were assigned to the elderly group and patients under 75 years old were assigned to the control group ( n=63). General data, American Society of Anesthesiologists (ASA) grading, procedure-related indicators, incidence of postoperative complications and mortality were compared. Results:There were significant differences in age (82.6±5.1 years VS 64.6±4.5 years, t=19.98, P<0.001), albumin levels (29.1±5.9 g/L VS 34.6±8.8 g/L, t=-3.94, P<0.001) and ASA grade ( χ2=8.37, P=0.015) in the elderly group and the control group . The elderly group were accompanied by more basic diseases, i.e. hypertension [57.14% (28/49) VS 34.9% (22/63), χ2=5.51, P=0.019], coronary heart disease [55.1% (27/49) VS 27.0% (17/63), χ2=9.14, P=0.003], chronic obstructive pulmonary diseases/asthma [24.5% (12/49) VS 6.3% (4/63), χ2=7.41, P=0.006]. There were no significant differences in the operation time (31.4±8.1 min VS 30.4±8.0 min, t=-0.61, P=0.543) or hospital stay (6.1±1.7 days VS 5.7±1.4 days, t=1.35, P=0.182). The incidences of postoperative complications were 14.3% (7/49) in the elderly group and 12.7% (8/63) in the control group, showing no significant difference ( χ2=0.06, P=0.807). No ERBD-related death was observed in either group during hospital stay. Conclusion:For elderly patients with AOSC over 75 years old, emergency ERBD, which can quickly relieve the disease, is safe and effective. Advanced age is not an absolute contraindication for emergency ERBD.

On the Sensing and Calibration of Residual Stresses Measurements in the Incremental Hole-Drilling Method.

The current study presents three calibration approaches for the hole-drilling method (HDM). A total of 72 finite element models and 144 simulations were established to calibrate the measurements of the strain sensors. The first approach assumed the stresses acted on the boundaries of the drilled hole and thus analyzed the surrounding displacements field. The second analysis considered the loads on the outer surfaces of the specimen while measuring the strains' differences between the model with and without the drilled hole. The third approach was more comprehensive as it considered the mechanical and thermal effects of the drilling operations. The proposed approaches were applied to two different materials (AISI 1045 and CFRP). The steel specimens were machined using a CNC lathe while the composite laminates were manufactured using the robotic fiber placement (RFP) process. Subsequently, the residual stresses (RSs) were measured using the HDM. The obtained data were compared with X-ray diffraction measurements for validation. The results showed better estimation of the RSs when utilizing the third approach and clear underestimation of the stresses using the second approach. A divergence in RSs values between the three approaches was also detected when measuring the stresses in the internal layers of the composite laminates.

Difluoromethyl Radical Triggered Tandem Reaction of N-Allyl Amides to Difluoromethylated ß-Amino Alcohols by Photoredox Catalysis.

An elegant tandem reaction process for transferring N-allyl amide into CF2H-ß-amino alcohol is described. This approach proceeded smoothly under visible light irradiation in the presence of a 3 mol % Ir complex, exhibiting a broad substrate scope and functional group tolerance, and a variety of CF2H-ß-amino alcohols were readily accessed in good to excellent yields under mild conditions. The reliable mechanistic studies revealed that sequential difluoromethyl radical addition/carbocation trap/rearrangement is involved.

Identifying Hybrid DDoS Attacks in Deterministic Machine-to-Machine Networks on a Per-Deterministic-Flow Basis.

The Deterministic Network (DetNet) is becoming a major feature for 5G and 6G networks to cope with the issue that conventional IT infrastructure cannot efficiently handle latency-sensitive data. The DetNet applies flow virtualization to satisfy time-critical flow requirements, but inevitably, DetNet flows and conventional flows interact/interfere with each other when sharing the same physical resources. This subsequently raises the hybrid DDoS security issue that high malicious traffic not only attacks the DetNet centralized controller itself but also attacks the links that DetNet flows pass through. Previous research focused on either the DDoS type of the centralized controller side or the link side. As DDoS attack techniques are evolving, Hybrid DDoS attacks can attack multiple targets (controllers or links) simultaneously, which are difficultly detected by previous DDoS detection methodologies. This study, therefore, proposes a Flow Differentiation Detector (FDD), a novel approach to detect Hybrid DDoS attacks. The FDD first applies a fuzzy-based mechanism, Target Link Selection, to determine the most valuable links for the DDoS link/server attacker and then statistically evaluates the traffic pattern flowing through these links. Furthermore, the contribution of this study is to deploy the FDD in the SDN controller OpenDayLight to implement a Hybrid DDoS attack detection system. The experimental results show that the FDD has superior detection accuracy (above 90%) than traditional methods under the situation of different ratios of Hybrid DDoS attacks and different types and scales of topology.

TcpC inhibits neutrophil extracellular trap formation by enhancing ubiquitination mediated degradation of peptidylarginine deiminase 4.

TcpC is a multifunctional virulence factor of uropathogenic E. coli (UPEC). Neutrophil extracellular trap formation (NETosis) is a crucial anti-infection mechanism of neutrophils. Here we show the influence of TcpC on NETosis and related mechanisms. We show NETosis in the context of a pyelonephritis mouse model induced by TcpC-secreting wild-type E. coli CFT073 (CFT073wt) and LPS-induced in vitro NETosis with CFT073wt or recombinant TcpC (rTcpC)-treated neutrophils are inhibited. rTcpC enters neutrophils through caveolin-mediated endocytosis and inhibits LPS-induced production of ROS, proinflammatory cytokines and protein but not mRNA levels of peptidylarginine deiminase 4 (PAD4). rTcpC treatment enhances PAD4 ubiquitination and accumulation in proteasomes. Moreover, in vitro ubiquitination kit analyses show that TcpC is a PAD4-targetd E3 ubiquitin-ligase. These data suggest that TcpC inhibits NETosis primarily by serving as an E3 ligase that promotes degradation of PAD4. Our findings provide a novel mechanism underlying TcpC-mediated innate immune evasion.

Single-dose AAV-based vaccine induces a high level of neutralizing antibodies and provides long-term protection against SARS-CoV-2 in rhesus macaques

Coronavirus disease 2019 (COVID-19), which is triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, continues to threaten global public health. Developing a vaccine that only requires single immunization but provides long-term protection for the prevention and control of COVID-19 is important. Here, we developed an adeno-associated virus (AAV)-based vaccine expressing a stable receptor-binding domain (SRBD) protein. The vaccine requires only a single shot but provides effective neutralizing antibodies (NAbs) over 598 days in rhesus macaques (Macaca mulatta). Importantly, our results showed that the NAbs were kept in high level and long lasting against authentic wild-type SARS-CoV-2, Beta, Delta and Omicron variants using plaque reduction neutralization test. Of note, although we detected pre-existing AAV2/9 antibodies before immunization, the vaccine still induced high and effective NAbs against COVID-19 in rhesus macaques. AAV-SRBD immune serum also efficiently inhibited the binding of ACE2 with RBD in the SARS-CoV-2 B.1.1.7 (Alpha), B.1.351 (Beta), P.1/P.2 (Gamma), B.1.617.2 (Delta), B.1.617.1/3(Kappa), and C.37 (Lambda) variants. Thus, these data suggest that the vaccine has great potential to prevent the spread of SARS-CoV-2.

Clinical efficacy of laparoscopic surgery for hepatic cystic echinococcosis: a meta-analysis / 中华肝胆外科杂志

Objective:To explore the curative effect of laparoscopic surgery for hepatic cysticercosis.Methods:Search the literature from February 2010 to February 2020 on literature platforms such as Wanfang Data, VIP, CNKI, Pubmed, ScienceDirect, Web of Science, etc. the key words were "肝囊型包虫病" , "细粒棘球蚴" , "手术" , "开腹手术" , "腹腔镜" , "微创手术" , " echinococcosis " , " liver or hepatic " , " laparoscopic or minimal invasive " . Data on intraoperative indicators (e.g., operation time, bleeding volume), postoperative complications, hospital stay, recurrence rate, etc. in the literature included in the study were extracted and meta-analyzed.Results:A total of 9 articles were included, including 2 prospective studies and 7 retrospective case-control studies. A total of 1031 patients were enrolled, including 272 in the laparoscopic group and 759 in the laparotomy group. The results of the meta-analysis showed that the total postoperative complication rate in the laparoscopic group was lower than that in the laparotomy group ( OR=1.64, 95% CI: 1.10-2.45, P<0.05). Incision-related complications in the laparoscopy group and laparotomy group the difference was statistically significant ( OR=2.81, 95% CI: 1.03-7.70, P<0.05), and the hospital stay in the laparoscopic group was shorter ( SMD=1.21, 95% CI: 0.47-1.96, P<0.05). There was no significant difference between the two groups in operation time, postoperative bile leakage, residual cavity infection and effusion, and postoperative recurrence rate ( P>0.05). Conclusions:Under the premise of strictly grasping the indication of laparoscopic surgery, the incidence of complications after laparoscopic surgery is low, the hospitalization time is short.

Enhancing the decolorization activity of Bacillus pumilus W3 CotA-laccase to Reactive Black 5 by site-saturation mutagenesis.

Reactive Black 5 (RB5) is a typical refractory azo dye. Widespread utilization of RB5 has caused a variety of environmental and health problems. The enzymatic degradation of RB5 can be a promising solution due to its superiority as an eco-friendly and cost-competitive process. Bacterial CotA-laccase shows great application prospect to eliminate hazardous dyes from wastewater. However, efficient decolorization of RB5 CotA-laccase generally requires the participation of costly, toxic mediators. In the present study, we modified the amino acids Thr415 and Thr418 near the type 1 copper site and the amino acid Gln442 at the entrance of the substrate-binding pocket of Bacillus pumilus W3 CotA-laccase to boost its RB5 decolorization activity based on molecular docking analysis and site-saturation mutagenesis. Through the strategies, two double site mutants T415D/Q442A and T418K/Q442A obtained demonstrated 43.94 and 52.64% RB5 decolorization rates in the absence of a mediator at pH 10.0, respectively, which were about 3.70- and 4.43-fold higher compared with the wild-type CotA-laccase. Unexpectedly, the catalytic efficiency of the T418K/Q442A to ABTS was enhanced by 5.33-fold compared with the wild-type CotA-laccase. The mechanisms of conferring enhanced activity to the mutants were proposed by structural analysis. In summary, the mutants T415D/Q442A and T418K/Q442A have good application potentials for the biodegradation of RB5. KEY POINTS: • Three amino acids of CotA-laccase were manipulated by site-saturation mutagenesis. • Decolorization rate of two mutants to RB5 was enhanced 3.70- and 4.43-fold, respectively. • The mechanisms of awarding enhanced activity to the mutants were supposed.

Recombinant Horseradish Peroxidase C1A Immobilized on Hydrogel Matrix for Dye Decolorization and Its Mechanism on Acid Blue 129 Decolorization.

In this study, horseradish peroxidase C1A (HRP C1A) from Armoracia rusticana was expressed in Escherichia coli as an inclusion body. Subsequently, an active recombinant HRP C1A was obtained by refolding gradually using dilution-ultrafiltration. The recombinant HRP C1A was immobilized on agarose-chitosan hydrogel at 86.9 ± 2.5% of immobilization efficiency. After immobilization of the recombinant HRP C1A, the pH and temperature stability were improved and the reusability of the recombinant HPR C1A was achieved. The immobilized HRP C1A activity was retained above 80% after 6 cycles. The immobilized recombinant HRP C1A was used for the decolorization of four various dyes, including acid blue 129 (AB129), methyl blue (MB), methyl red (MR), and trypan blue (TB). The decolorization rates are all more than 70%, among which the decolorization effect of AB129 was the most significant (the decolorization rate was 76.3 ± 1.6%). Furthermore, a plausible decolorization pathway for AB129 was proposed based on the identified intermediates by ultraperformance liquid chromatography coupled with mass spectrometry (UPLC-MS). This is the first report of the putative mechanism on the decolorization of AB129 by HRP.

Successful surgical treatment of Cronkhite-Canada Syndrome with bilateral flail chest: a case report.

BACKGROUND: Development of multiple rib fractures leading to bilateral flail chest in Cronkhite-Canada Syndrome (CCS) has not been reported. CASE PRESENTATION: A 59-year-old man presented with complaints of fatigue, chest pain, respiratory distress and orthopnea requiring ventilatory support to maintain oxygenation. CCS with bilateral anterior and posterior flail chest due to multiple rib fractures (2nd-10th on the right side and 2nd-11th on the left side). He underwent open reduction and anterior and posterior internal fixation using a titanium alloy fixator and a nickel-titanium memory alloy embracing fixator for chest wall reconstruction. He recovered gradually from the ventilator and showed improvement in his symptoms. He gained about 20 kg of weight in the follow up period (6 months after discharge from the hospital). CONCLUSION: CCS is a rare, complex disease that increases the risk of developing multiple rib fractures, which can be successfully treated with open reduction and internal fixation.

Extracellular expression of mutant CotA-laccase SF in Escherichia coli and its degradation of malachite green.

In this study, mutant CotA-laccase SF was successfully expressed in Escherichia coli by co-expression with phospholipase C. The optimized extracellular expression of CotA-laccase SF was 1257.22 U/L. Extracellularly expressed CotA-laccase SF exhibits enzymatic properties similar to intracellular CotA-laccase SF. CotA-laccase SF could decolorize malachite green (MG) under neutral and alkaline conditions. The Km and kcat values of CotA-laccase SF to MG were 39.6 mM and 18.36 s-1. LC-MS analysis of degradation products showed that MG was finally transformed into 4-aminobenzophenone and 4-aminophenol by CotA-laccase. The toxicity experiment of garlic root tip cell showed that the toxicity of MG metabolites decreased. In summary, CotA-laccase SF had a good application prospect for degrading malachite green.

Enhancement in catalytic activity of CotA-laccase from Bacillus pumilus W3 via site-directed mutagenesis.

CotA-laccases are potential enzymes that are widely used in decolorization of dyes and degradation of toxic substances. In this study, a novel CotA-laccase gene from Bacillus pumilus W3 was applied for rational design. After a series of site-directed genetic mutations, the mutant S208G/F227A showed a 5.1-fold higher catalytic efficiency (kcat/Km) than the wild-type CotA-laccase did. The optimal pH of S208G/F227A was 3.5 with ABTS as substrate. The residual activity of mutant S208G/F227A was more than 80% after incubated for 10 h at pH 7-11. Mutant S208G/F227A showed optimal temperature at 80°C with ABTS as substrate. The thermal stability of mutant laccase S208G/F227A was lower than that of wild-type CotA-laccase. This study showed that Gly208 and Ala227 play key roles in catalytic efficiency and it is possible to improve catalytic efficiency of CotA-laccase through site-directed mutagenesis.

Surveillance of Oncomelania hupensis distribution and water levels in Gaoyou sections of the eastern route project of the South-to-North Water Diversion Project following operation of the project / 中国血吸虫病防治杂志

Objective To understand the distribution of Oncomelania hupensis snails and changes of water levels in Gaoyou sections of the Li Canal following the operation of the eastern route project of the South-to-North Water Diversion Project. Methods The Oncomelania snails were monitored in the river banks and water bodies of Gaoyou sections of the Li Canal by means of systematic sampling combined with environmental sampling as well as collection of the floaters from 2014 to 2019, and the water levels were collected in Gaoyou sections of the Li Canal at the typical hydrological year before the operation of the eastern route project of the South-to-North Water Diversion Project and during the period between 2016 and 2019. Results A total area of 235.42 hm2 were investigated and a total of 75.8 kg floaters were collected in Gaoyou sections of the Li Canal from 2014 to 2019; however, no snails were found. The water level in Gaoyou sections of the Li Canal was predominantly high in the flood season and low in the dry season before the operation of the eastern route project of the South-to-North Water Diversion Project, and the water level was elevated in the dry season and relatively low in the flood season after the operation of the project. Conclusion Following the operation of the eastern route project of the South-to-North Water Diversion Project, the original river bank that is characterized by “land in winter and water in summer” has changed in Gaoyou sections of the Li Canal, which is not favorable for snail breeding.

Imaging Analysis of Ganglioneuroma and Quantitative Analysis of Paraspinal Ganglioneuroma.

BACKGROUND This study evaluated the imaging features of ganglioneuroma (GN) and assessed the diagnostic value of the enhancement rate (ER) of CT for GN. MATERIAL AND METHODS We retrospectively reviewed records of 49 patients with histopathologically confirmed GN who underwent preoperative contrast-enhanced CT or MRI between 2010 and 2018. The independent samples t test and chi-square test were used. Receiver operating characteristic (ROC) curves were generated to analyze the diagnostic sensitivity (SE) and specificity (SP). Positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS The CT values were 32.59±3.61 Hounsfield units (HU) for plain scans, 38.87±5.09 HU for the arterial phase, and 54.26±8.14 HU for the venous phase, and the incidence of calcification and cysts was 32.6% and 10.2%, respectively. There was no significant difference in CT results and clinical parameters between mediastinal ganglioneuroma (MGN) and retroperitoneal ganglioneuroma (RGN) (p>0.05). The area under the curves (AUCs) for the arterial enhancement rate (AER), venous enhancement rate (VER), and AER/VER combined index in diagnosing GN were 0.735, 0.980, and 0.990, respectively. The VER of 0.2819 exhibited the SE and SP at 92.9% and 92.9%, respectively, to characterize the GN, whereas the AER of 0.1779 had SE and SP of 52.4% and 90.5%, respectively. The SE and SP for the combined index were 88.1% and 100%, respectively. The GN showed hypointensity on T1WI, hyperintense, or slightly high signal on T2WI with the linear hypointensity, and hyperintense on DWI. CONCLUSIONS A hypodense mass was observed for GN on plain scan and presented delayed enhancement on contrast enhancement. VER or AER/VER combination is more accurate than AER for the diagnosis of paravertebral GN.

An radio frequency coil design for rat spinal magnetic resonance imaging at 9.4 T / 生物医学工程学杂志

For rat spinal magnetic resonance imaging (MRI) experiments, due to the lower main magnetic field strength, shallower detected depth and poor spatial compatibility of the traditional radio frequency (RF) coil, the image signal-to-noise ratio (SNR) of rat spinal was rather lower. In this paper, a RF coil for rat spinal MRI at 9.4 T was developed to improve the image quality and at the same time to avoid the space limitation while scanning in special conditions (cardiac catheterization, etc.). In this article, open birdcage structure was built and magnetic field distribution was calculated. The phantom and rat spine MRI imaging were experimented at 9.4 T to verify the advantage of the coil in rat spine MRI application.

Quantitative susceptibility mapping of ultra-high resolution monkey brain in vivo at 9.4 T / 生物医学工程学杂志

Quantitative susceptibility mapping (QSM) can provide tissue susceptibility information and has been adapted for clinical research and diagnosis. QSM of monkey brain at 9.4 T has not been demonstrated so far. In this study 9.4 T monkey brain QSM was performed with 200 μm isotropic high-resolution. It was found that the inherent singularity problem for QSM diverged significantly at ultra-high image resolution during regularization process and resulted in severe image artifacts. The K-space division (TKD) was applied to eliminate the artifacts, with an optimal threshold level between 0.2 and 0.3. High resolution QSM of monkey brain can thus provide a novel tool for brain research.