Establishment of a mandible defect model in rabbits infected with multiple bacteria and bioinformatics analysis.

Objective: A model of chronic infectious mandibular defect (IMD) caused by mixed infection with Staphylococcus aureus and Pseudomonas aeruginosa was established to explore the occurrence and development of IMD and identify key genes by transcriptome sequencing and bioinformatics analysis. Methods: S. aureus and P. aeruginosa were diluted to 3 × 108 CFU/mL, and 6 × 3 × 3 mm defects lateral to the Mandibular Symphysis were induced in 28 New Zealand rabbits. Sodium Morrhuate (0.5%) and 50 µL bacterial solution were injected in turn. The modeling was completed after the bone wax closed; the effects were evaluated through postoperative observations, imaging and histological analyses. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and protein‒protein interaction (PPI) network analyses were performed to investigate the function of the differentially expressed genes (DEGs). Results: All rabbits showed characteristics of infection. The bacterial cultures were positive, and polymerase chain reaction (PCR) was used to identify S. aureus and P. aeruginosa. Cone beam CT and histological analyses showed inflammatory cell infiltration, pus formation in the medullary cavity, increased osteoclast activity in the defect area, and blurring at the edge of the bone defect. Bioinformatics analysis showed 1,804 DEGs, 743 were upregulated and 1,061 were downregulated. GO and KEGG analyses showed that the DEGs were enriched in immunity and osteogenesis inhibition, and the core genes identified by the PPI network were enriched in the Hedgehog pathway, which plays a role in inflammation and tissue repair; the MEF2 transcription factor family was predicted by IRegulon. Conclusion: By direct injection of bacterial solution into the rabbit mandible defect area, the rabbit chronic IMD model was successfully established. Based on the bioinformatics analysis, we speculate that the Hedgehog pathway and the MEF2 transcription factor family may be potential intervention targets for repairing IMD.

Clinical efficacy of transcrestal sinus floor augmentation, in comparison with lateral approach, in sites with residual bone height ≤6 mm: A systematic review and meta-analysis.

OBJECTIVE: This paper addressed two focused questions: Focused question 1 (Q1) "what is the clinical efficacy of transcrestal sinus floor augmentation (TSFA), as compared to lateral sinus floor augmentation (LSFA) in sites with residual bone height (RBH) ≤6 mm, in randomized clinical trials (RCTs) and controlled clinical trials (CCTs)?"; Focused question 2 (Q2) "what is the estimated effectiveness of TSFA for outcomes in Q1, in RCTs, CCTs or cohort studies?" MATERIALS AND METHODS: An electronic search (PubMed, EMBASE, The Cochrane Central Register of Controlled Trials) and hand search were conducted from January 1986 until December 2022. All eligible clinical studies expressly reporting TSFA in sites with RBH ≤6 mm were included. The data were extracted, and the risk of bias in individual studies was evaluated. Meta-analysis was performed whenever possible. RESULTS: Seven RCTs were included for Q1 and 25 studies (9 RCTs, 2 CCTs, 14 single arm cohort studies) for Q2. Q1: Meta-analysis did not show significant difference in the implant survival, sinus membrane perforation and marginal bone loss between TSFA and LSFA groups. Q2: Meta-analysis showed TSFA had a high implant survival rate (96.5%, 95% CI: 93.2%-98.9%) at least 1 year after surgery, and limited sinus membrane perforation (5.4%, 95% CI: 2.7%-8.8%). The results also presented higher patient satisfaction for TSFA. CONCLUSION: With the limitations of the present study (high risk of bias in individual studies), it can be concluded that there was no significant difference in implant survival, Schneiderian membrane perforation and MBL between two approaches in sites with RBH ≤6 mm.

Enantioselective Dearomatization of Indoles via SmI2-Mediated Intermolecular Reductive Coupling with Ketones.

Samarium diiodide (SmI2) mediated reductive coupling reactions are powerful methods for the construction of carbon-carbon bond in organic synthesis. Despite the extensive development in recent decades, successful examples of the corresponding asymmetric reactions remained scarce, probably due to the involvement of highly reactive radical intermediates. In this Article, we report an enantioselective dearomatization of indoles via SmI2-mediated intermolecular reductive coupling with ketones. The utilization of samarium reductant supported by chiral tridentate aminodiol ligands allows the facile synthesis of indoline molecules bearing two contiguous stereogenic centers in high yields (up to 99%) and stereoselectivity (up to 99:1 er and >20:1 dr). Combined experimental and computational investigations suggested that parallel single-electron transfer to each substrate from the chiral samarium reductant allows the radical-radical recombination in an enantioselective manner, which is a unique mechanistic scenario in SmI2-mediated reductive coupling reactions.

Effects of oleanolic acid on hair growth in mouse dorsal skin mediated via regulation of inflammatory cytokines.

Oleanolic acid (OA) is a pentacyclic triterpenoid with favourable physiological activity. It is widely distributed in more than 200 species of plants. OA has garnered significant interest because of its potential biological activities, such as antioxidant, bacteriostatic, and hair growth-promoting effects. To study the effect of OA on hair growth and related mechanisms, we investigated hair growth in mice with testosterone-induced androgenetic alopecia (AGA) that were treated with three different concentrations of OA. The antioxidant, bacteriostatic, and cytotoxic effects of OA were evaluated. We found that mice with testosterone-induced AGA treated with 1% or 0.5% OA showed significantly enhanced hair growth and increased vascular endothelial growth factor/glyceraldehyde-3-phosphate dehydrogenase ratio and levels of fibroblast growth factor receptor and insulin-like growth factor 1. Using an immunofluorescence staining assay, we demonstrated that ß-catenin, a key Wnt signalling transducer, was highly expressed in the OA-treated groups. These results suggest that OA may promote hair growth by stimulating hair matrix cell proliferation via the Wnt/ß-catenin pathway and lowering the levels of tumour necrosis factor-alpha, and transforming growth factor-beta 1, dihydrotestosterone, and 5α-reductase.

Cobalt(III)-catalyzed asymmetric ring-opening of 7-oxabenzonorbornadienes via indole C-H functionalization.

Asymmetric ring-opening of 7-oxabenzonorbornadienes is achieved via Co-catalyzed indole C-H functionalization. The utilization of chiral Co-catalyst consisting of a binaphthyl-derived trisubstituted cyclopentadienyl ligand resulted in high yields (up to 99%) and excellent enantioselectivity (>99% ee) for the target products with tolerance for diverse functional groups. Opposite diastereoselectivities are obtained with chiral Co-catalyst or Cp*CoI2CO. Combined experimental and computational studies suggest ß-oxygen elimination being the selectivity-determining step of the reaction. Meanwhile, the reactions of 7-azabenzonorbornadiene could also be executed in a diastereodivergent manner.

Autistic Traits and Empathy for Others' Pain Among the General Population: Test of the Mediating Effects of First-Hand Pain Sensitivity.

Autism spectrum disorders (ASD) are characterized by reduced pain empathy-a process that is grounded in first-hand pain perception. Because autistic traits are continuously distributed in the general population, we hypothesized that first-hand pain sensitivity would mediate the link between autistic traits and pain empathy. After controlling for alexithymia, higher autistic traits were associated with lower cognitive and emotional empathy in response to others' pain, as well as lower sensitivity to cold and heat pain (higher cold pain tolerance and lower laser heat pain-intensity ratings). Importantly, pain sensitivity fully mediated the link between autistic traits and pain empathy. These findings highlight the role of atypical first-hand pain sensitivity in the lack of pain empathy observed in people with high autistic traits or ASD.

Gyrus rectus asymmetry predicts trait alexithymia, cognitive empathy, and social function in neurotypical adults.

Reduced empathy and elevated alexithymia are observed in autism spectrum disorder (ASD), which has been linked to altered asymmetry in brain morphology. Here, we investigated whether trait autism, empathy, and alexithymia in the general population is associated with brain morphological asymmetry. We determined left-right asymmetry indexes for cortical thickness and cortical surface area (CSA) and applied these features to a support-vector regression model that predicted trait autism, empathy, and alexithymia. Results showed that less leftward asymmetry of CSA in the gyrus rectus (a subregion of the orbitofrontal cortex) predicted more difficulties in social functioning, as well as reduced cognitive empathy and elevated trait alexithymia. Meta-analytic decoding of the left gyrus rectus annotated functional items related to social cognition. Furthermore, the link between gyrus rectus asymmetry and social difficulties was accounted by trait alexithymia and cognitive empathy. These results suggest that gyrus rectus asymmetry could be a shared neural correlate among trait alexithymia, cognitive empathy, and social functioning in neurotypical adults. Left-right asymmetry of gyrus rectus influenced social functioning by affecting the cognitive processes of emotions in the self and others. Interventions that increase leftward asymmetry of the gyrus rectus might improve social functioning for individuals with ASD.

Concrescence of maxillary second molar and impacted third molar: A case report.

BACKGROUND: Morphological anomalies of teeth, including talon cusp, dens evaginatus, gemination, fusion, concrescence, root dilaceration, and taurodontism, always involve changes in the enamel, cementum and dentin. Diagnosing concrescent teeth through routine clinical examination alone is difficult, and most cases of concrescence are found accidentally during extraction. A definite preoperative diagnosis of concrescence would contribute to a better treatment plan and fewer undesirable complications. CASE SUMMARY: A 47-year-old woman who complained of left maxillary first molar loss for half a year presented to our department seeking treatment by dental implant restoration. Panoramic radiography and cone-beam computed tomography (CBCT) showed an unclear boundary between the distal root of the second molar and the mesial root of the third molar. The teeth were extracted under local anesthesia, and a definite diagnosis of concrescence was made by histopathological examination. CONCLUSION: CBCT is a useful tool for diagnosing and planning the management of tooth concrescence and may be beneficial for reducing unnecessary complications.

Ongoing first-hand pain facilitates somatosensory resonance but inhibits affective sharing in empathy for pain.

Alterations of empathy for others' pain among patients with chronic pain remained inconsistent. Here, applying a capsaicin-based ongoing pain model on healthy participants, this study investigated how ongoing first-hand pain influences empathic reactions to vicarious pain stimuli. Healthy participants were randomly treated with topical capsaicin cream (capsaicin group) or hand cream (control group) on the left forearm. Video clips showing limbs in painful and non-painful situations were used to induce empathic responses. The capsaicin group showed greater empathic neural responses in the right primary somatosensory cortex (S1) than the control group but smaller responses in the left anterior insula (AI) accompanied with smaller empathic pain-intensity ratings. Notably, the intensity of ongoing pain negatively correlated with empathy-related neural responses in the left AI. Inter-subject phase synchronization analysis was used to assess stimulus-dependent dynamic functional connectivity within or between brain regions engaged in pain empathy. The capsaicin group showed greater empathy-related neural synchronization within S1 and between S1 and AI, but less synchronization within AI and between AI and MCC. Behaviorally, the differential inter-subject pain-intensity rating alignment between painful and non-painful videos was more positive for the capsaicin group than for the control group, and this effect was partially mediated by the inter-subject neural synchronization between S1 and AI. These results suggest that ongoing first-hand pain facilitates neural activation and synchronization within brain regions associated with empathy-related somatosensory resonance at the cost of inhibiting activation and synchronization within brain regions engaged in empathy-related affective sharing.

Single-dose testosterone administration modulates instant empathic responses to others' pain: An EEG study.

Whether or not testosterone can impair empathy remains unclear in the literature. Given that empathic responses to others' emotional experiences depend strongly upon top-down controlled mechanisms of attention, here we investigated whether the effects of testosterone administration on pain empathy could be modulated by manipulating attention. We used a double-blind, placebo-controlled within-participant design, in which either testosterone or placebo was administrated in separate sessions. Images depicting painful or nonpainful scenes were presented to induce instant empathic responses. Experiment 1 adopted the pain-judgment and hands-counting tasks to direct attention toward painful or nonpainful aspect of the images, respectively. Experiment 2 employed the pain-rating task to estimate affective and cognitive aspects of pain empathy. When discriminating nonpainful aspects of the images in the hands-counting task, accuracies were lower and empathic late positive potential responses were greater in testosterone sessions than in placebo sessions. This suggested that testosterone enhanced empathic responses to task-irrelevant pain-related features, which interfered with task performance. When providing empathic ratings to the images in the pain-rating task, empathic event-related potentials in the early stage were only observed in the testosterone session. This suggested that testosterone facilitated automatic affective reactivity to others' pain when elaborately processing empathic stimuli. Nevertheless, when discriminating painful aspects of the images in the pain-judgment task, we did not observe any significant differences between the two sessions. These results demonstrated that testosterone effects on enhancing brain reactivity to empathic stimuli were dependent upon task demands deploying attention allocation. The enhancement likely arose from the altered brain state (e.g., increased vigilance and arousal levels) after testosterone administration, as evidenced by the reduced amplitude of spontaneous α-oscillation recorded before the onset of the images. It expands our understanding of the neurobiological mechanisms that affect empathy, and highlights the role of testosterone.

Iridium-Catalyzed Asymmetric Allylic Substitution of Methyl Azaarenes.

Herein, an Ir-catalyzed asymmetric allylic substitution reaction of methyl azaarenes is described. Azaarenes such as (benzo)thiazole, oxazole, benzoimidazole, pyridine, and (iso)quinoline are all tolerated. The corresponding chiral azaarene derivatives are obtained in good yields with high enantioselectivity (up to 96 % yield and 99 % ee). The utilization of the Knochel reagent TMPZnBr⋅LiBr warrants the in situ formation of benzylic nucleophiles without additional activating reagents. 1 H NMR studies suggested a two-fold function of the Knochel reagent in this reaction. The synthetic utility of this method has been showcased by a concise enantioselective synthesis of an allosteric protein kinase modulator.

Characteristics and accurate identification of Pantoea dispersa with a case of spontaneous rupture of hepatocellular carcinoma in China: A case report.

INTRODUCTION: Pantoea dispersa belongs to the genus Pantoea, which is isolated from Enterobacteriaceae. It has been reported to cause some kinds of infections, but there are few detailed studies on it, especially its characteristics and identification methods, which has caused a lot of trouble in clinical work. PATIENT CONCERNS: A 51-year-old Chinese man was admitted to our hospital with a 7-hour history of progressive abdominal pain. He was previously diagnosed with liver cirrhosis secondary to chronic hepatitis B infection and hepatocellular carcinoma. An emergency hepatic artery embolization for hemostasis was performed under local anesthesia. Forty-eight hours later, the patient presented sudden onset of high fever up to 39.0 °C and chill. DIAGNOSIS: Morphological and phenotypic profiles were performed for preliminary identification for P dispersa. The biochemical features were obtained by VITEK 2 Test Kit. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis and 16S ribosomal RNA sequencing were performed to accurately identify P dispersa. INTERVENTION: Antibiotic therapy of intravenous ceftazidime was started empirically. The antibiotic treatment was switched to intravenous cefepime at the same time because of suspected ceftazidime treatment failure and microbiological sensitivity. OUTCOMES: The patient remained afebrile, and the second blood culture results were negative. Chest X-ray was normal as well. In order to control the progression of the hepatic lesion, transarterial chemoembolization was performed under local anesthesia. After completion of 14 days of antibiotic treatment, the patient was discharged with no signs of recurrence. CONCLUSION: P dispersa, a gram-negative bacterium rod, were facultative anaerobic, which displayed yellow pigmentation, round, raised, smooth on culture plates. Conventional analysis was difficult to complete its identification. With biochemical tests, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis and 16S ribosomal RNA sequencing, P dispersa can be accurately identified. It will help physicians understand the related clinical manifestations and make timely and effective treatment for patients.

Bloodstream infection caused by Bacteroides caccae in a patient with renal hypertension: a case report.

Bacteroides caccae is an anaerobic bacterium with a reportedly high isolation rate; however, it rarely causes bloodstream infections. Patients with hypertension are at increased risk of developing anaerobic bacterial infection. In this study, we report a case of bacteremia caused by B. caccae in a patient with renal hypertension and gastrointestinal hemorrhage. This study describes the clinical manifestations of bloodstream infection involving B. caccae to provide guidance for laboratory technicians and clinicians. A 42-year-old Chinese man was admitted for gastrointestinal hemorrhage and subsequently diagnosed with anaerobic blood infection. The pathogenic bacteria isolated from anaerobic blood culture bottles were identified as B. caccae by using an automatic bacterial identification instrument and mass spectrometry (MS). B. caccae is an intestinal opportunistic pathogen that can invade the intestinal mucosa and cause anaerobic bloodstream infection. Two or more sets of blood cultures and MS identification can greatly improve the positive detection rate of blood cultures of anaerobic bacteria. Furthermore, the increased drug resistance of anaerobic bacteria necessitates drug sensitivity tests for anaerobic bacteria in many hospitals. Thus, the early prevention and control of primary diseases with appropriate diagnoses and timely anti-infection therapies are necessary to reduce B. caccae bloodstream infection.

Analgesia induced by anodal tDCS and high-frequency tRNS over the motor cortex: Immediate and sustained effects on pain perception.

BACKGROUND: Many studies have shown effects of anodal transcranial direct current stimulation (a-tDCS) and high-frequency transcranial random noise stimulation (tRNS) on elevating cortical excitability. Moreover, tRNS with a direct current (DC)-offset is more likely to lead to increases in cortical excitability than solely tRNS. While a-tDCS over primary motor cortex (M1) has been shown to attenuate pain perception, tRNS + DC-offset may prove as an effective means for pain relief. OBJECTIVE: This study aimed to examine effects of a-tDCS and high-frequency tRNS + DC-offset over M1 on pain expectation and perception, and assess whether these effects could be influenced by the certainty of pain expectation. METHODS: Using a double-blinded and sham-controlled design, 150 healthy participants were recruited to receive a single-session a-tDCS, high-frequency tRNS + DC-offset, or sham stimulation over M1. The expectation and perception of electrical stimulation in certain and uncertain contexts were assessed at baseline, immediately after, and 30 min after stimulation. RESULTS: Compared with sham stimulation, a-tDCS induced immediate analgesic effects that were greater when the stimulation outcome was expected with uncertainty; tRNS induced immediate and sustained analgesic effects that were mediated by decreasing pain expectation. Nevertheless, we found no strong evidence for tRNS being more effective for attenuating pain than a-tDCS. CONCLUSIONS: The analgesic effects of a-tDCS and tRNS showed different temporal courses, which could be related to the more sustained effectiveness of high-frequency tRNS + DC-offset in elevating cortical excitability. Moreover, expectations of pain intensity should be taken into consideration to maximize the benefits of neuromodulation.

Effects of transcranial direct current stimulation on experimental pain perception: A systematic review and meta-analysis.

OBJECTIVE: Many studies have examined the effectiveness of transcranial direct current stimulation (tDCS) on human pain perception in both healthy populations and pain patients. Nevertheless, studies have yielded conflicting results, likely due to differences in stimulation parameters, experimental paradigms, and outcome measures. Human experimental pain models that utilize indices of pain in response to well-controlled noxious stimuli can avoid many confounds present in clinical data. This study aimed to assess the robustness of tDCS effects on experimental pain perception among healthy populations. METHODS: We conducted three meta-analyses that analyzed tDCS effects on ratings of perceived pain intensity to suprathreshold noxious stimuli, pain threshold and tolerance. RESULTS: The meta-analyses showed a statically significant tDCS effect on attenuating pain-intensity ratings to suprathreshold noxious stimuli. In contrast, tDCS effects on pain threshold and pain tolerance were statistically non-significant. Moderator analysis further suggested that stimulation parameters (active electrode size and current density) and experimental pain modality moderated the effectiveness of tDCS in attenuating pain-intensity ratings. CONCLUSION: The effectiveness of tDCS on attenuating experimental pain perception depends on both stimulation parameters of tDCS and the modality of experimental pain. SIGNIFICANCE: This study provides some theoretical basis for the application of tDCS in pain management.

Single dose testosterone administration enhances novelty responsiveness and short-term habituation in healthy males.

The role of testosterone in sensory perception suggests that testosterone likely regulates adaptive responses to sensory changes, including habituation to repeated events and responsiveness to novel events. To test this hypothesis, we investigated how testosterone modulates brain responses to rapid changes in sensory inputs. Using a double-blind, placebo-controlled, within-participant design, each participant received a single dose of either testosterone or placebo, and then completed a passive auditory oddball task in which infrequent deviant tones were embedded in a series of frequent standard tones. Analysis of novelty-evoked potentials revealed smaller Mismatch Negativity (MMN) responses, but larger P3a responses in the testosterone session than in the placebo session. This suggests testosterone attenuates MMN responses that are associated with pre-attentive novelty detection and enhances P3a responses that are associated with involuntary attentional orientation toward novelty. Along with the repetition of standard tones, P2 responses on the auditory evoked potentials became significantly attenuated in the testosterone session, but not in the placebo session. This suggests testosterone enhances short-term habituation of P2 responses to recurring sensory events, which has been associated with bottom-up attention allocation. Mediation analysis further revealed that the role of testosterone in promoting attentional orientation toward novelty could be explained by the influence it exerts on short-term habituation and pre-attentive novelty detection. Overall, testosterone facilitated involuntary attention switching-withdrawal of attention from repeated sensory events and orientation toward novel sensory events-at the cost of attenuated pre-attentive novelty detection. This finding provides insight into the interplay between endocrinology and involuntary attentional processes.

Enantioselective Desymmetrization of Bisphenol Derivatives via Ir-Catalyzed Allylic Dearomatization.

Spirocyclic hexadienones with multiple stereogenic centers are frequently found in natural products but remain challenging targets to synthesize. Herein, we report the enantioselective desymmetrization of bisphenol derivatives via Ir-catalyzed allylic dearomatization reactions, affording spirocyclic hexadienone derivatives with up to three contiguous stereogenic centers in good yields (up to 90%) and excellent enantioselectivity (up to 99% ee). The high efficiency of this reaction is exemplified by the short reaction time (30 min), low catalyst loading (down to 0.2 mol %), and ability to perform the reaction on a gram-scale. The total syntheses of (+)-tatanan B and (+)-tatanan C were also realized using this Ir-catalyzed allylic dearomatization reaction as a key step.

The MYB transcription factor TaPHR3-A1 is involved in phosphate signaling and governs yield-related traits in bread wheat.

Improved inorganic phosphate (Pi) use efficiency in crops will be important for sustainable agriculture. Exploring molecular mechanisms that regulate Pi uptake could provide useful information for breeding wheat with improved Pi use efficiency. Here, a TaPHR3-A1 (Gene ID: TraesCS7A02G415800) ortholog of rice OsPHR3 that functions in transcriptional regulation of Pi signaling was cloned from wheat chromosome 7A. Ectopic expression of TaPHR3-A1 in Arabidopsis and rice produced enhanced vegetative growth and more seeds. Overexpression in transgenic rice led to increased biomass, grain number, and primary panicle branching by 61.23, 42.12, and 36.34% compared with the wild type. Transgenic wheat lines with down-regulation of TaPHR3-A1 exhibited retarded growth and root hair development at the seedling stage, and showed yield-related effects at the adult stage when grown in both low- and sufficient Pi conditions, indicating that TaPHR3-A1 positively regulated tolerance to low Pi. Introgression lines further confirmed the effect of TaPHR3-A1 in improving grain number. The Chinese wheat mini core collection and a recombinant inbred line analysis demonstrated that the favorable allele TaPHR3-A1-A associated with higher grain number was positively selected in breeding. A TaPHR3-A1-derived cleaved amplified polymorphic sequence marker effectively identified haplotype TaPHR3-A1-A. Our results suggested that TaPHR3-A1 was a functional regulatory factor for Pi uptake and provided useful information for marker-assisted selection for high yield in wheat.

Sequence-Dependent Stereodivergent Allylic Alkylation/Fluorination of Acyclic Ketones.

The stereodivergent iridium-catalyzed allylic alkylation and fluorination of acyclic ketones is described. α-Pyridyl-α-fluoroketones with vicinal tertiary and quaternary stereocenters were obtained in moderate to excellent yields and stereoselectivities. Distinct from known stereodivergent synthesis, for which two different chiral catalysts are required in general, herein we report a sequence-dependent stereodivergent synthesis. With only a single chiral Ir catalyst, all four possible stereoisomers of the products were prepared from the same starting materials by simply adjusting the sequence of asymmetric allylic alkylation and fluorination and varying the absolute configuration of the Ir catalyst.

[Effect of two kinds of surface pretreatments on bending strength to the modified polyetheretherketone].

OBJECTIVE: To evaluate the effect of sandblasting or acid etching on the three-point bending strength to the modified polyetheretherketone (PEEK). METHODS: Forty-eight bars (15 mm×2 mm×1 mm) of specimens were fabricated from the modified PEEK (BioHPP). They were randomly divided into the following groups: A, B, C and D groups, which were blasted with alumina particles; E, F, and G groups, which were etched with 98% concentrated sulfuric acid; and control group H. The sand blast pressure of groups A, B and C was 0.2 MPa, and the grain sizes of the sand blasted were 120, 50, and 250 µm, respectively. Group D was blasted with 120 µm particle size at 0.7 MPa pressure. Groups E, F and G were acid etched for 60, 120, and 300 s, respectively. No surface treatment was conducted in group H. After all the specimens were processed, one sample was randomly selected from each group to observe its surface morphology under a scanning electron microscope (SEM), and the other specimens were tested for their three-point bending strength. SPSS 22.0 software was used to analyze the experimental data and to test whether the difference was statistically significant. RESULTS: SEM observation showed that the surface morphology of the specimen changed after the treatment and revealed different degrees of cracks, pits, or voids. The three-point bending test indicated that the strength of the specimens treated with sandblasting or concentrated sulfuric acid decreased compared with that of the control group (P<0.05). At the same pressure, no significant difference in flexural strength was observed among groups A, B, and C (P>0.05). The strength of group D was lower than that of group A at the same particle size (P<0.05), and no significant difference was found in the bending strength of the specimens etched with concentrated sulfuric acid (P>0.05). CONCLUSIONS: The bending strength of BioHPP could be significantly decreased by surface sand blasting or concentrated sulfate etching as the sandblasting pressure increased, but the bending strength did not decrease as sand particle size and acid etching time changed.