Isoreticular Contraction of Cage-like Metal-Organic Frameworks with Optimized Pore Space for Enhanced C2H2/CO2 and C2H2/C2H4 Separations.

The C2H2 separation from CO2 and C2H4 is of great importance yet highly challenging in the petrochemical industry, owing to their similar physical and chemical properties. Herein, the pore nanospace engineering of cage-like mixed-ligand MFOF-1 has been accomplished via contracting the size of the pyridine- and carboxylic acid-functionalized linkers and introducing a fluoride- and sulfate-bridging cobalt cluster, based on a reticular chemistry strategy. Compared with the prototypical MFOF-1, the constructed FJUT-1 with the same topology presents significantly improved C2H2 adsorption capacity, and selective C2H2 separation performance due to the reduced cage cavity size, functionalized pore surface, and appropriate pore volume. The introduction of fluoride- and sulfate-bridging cubane-type tetranuclear cobalt clusters bestows FJUT-1 with exceptional chemical stability under harsh conditions while providing multiple potential C2H2 binding sites, thus rendering the adequate ability for practical C2H2 separation application as confirmed by the dynamic breakthrough experiments under dry and humid conditions. Additionally, the distinct binding mechanism is suggested by theoretical calculations in which the multiple supramolecular interactions involving C-H···O, C-H···F, and other van der Waals forces play a critical role in the selective C2H2 separation.

Tailoring Broadband Nonlinear Optical Characteristics and Ultrafast Photocarrier Dynamics of Bi2O2S Nanosheets by Defect Engineering.

Low-dimensional bismuth oxychalcogenides have shown promising potential in optoelectronics due to their high stability, photoresponse, and carrier mobility. However, the relevant studies on deep understanding for Bi2O2S is quite limited. Here, comprehensive experimental and computational investigations are conducted in the regulated band structure, nonlinear optical (NLO) characteristics, and carrier dynamics of Bi2O2S nanosheets via defect engineering, taking O vacancy (OV) and substitutional Se doping as examples. As the OV continuously increased to ≈35%, the optical bandgaps progressively narrow from ≈1.21 to ≈0.81 eV and NLO wavelengths are extended to near-infrared regions with enhanced saturable absorption. Simultaneously, the relaxation processes are effectively accelerated from tens of picoseconds to several picoseconds, as the generated defect energy levels can serve as both additional absorption cross-sections and fast relaxation channels supported by theoretical calculations. Furthermore, substitutional Se doping in Bi2O2S nanosheets also modulate their optical properties with the similar trends. As a proof-of-concept, passively mode-locked pulsed lasers in the ≈1.0 µm based on the defect-rich samples (≈35% OV and ≈50% Se-doping) exhibit excellent performance. This work deepens the insight of defect functions on optical properties of Bi2O2S nanosheets and provides new avenues for designing advanced photonic devices based on low-dimensional bismuth oxychalcogenides.

Odontogenic infections in the antibiotic era: approach to diagnosis, management, and prevention.

PURPOSE: The prevalence of odontogenic infections remains one of the highest in the world. If untreated, odontogenic infections can break through the limitation, disseminate to other organs or spaces, and cause high mortality rates. However, it is still difficult to rapidly target limited or disseminated infections in clinical practice. The type of disseminated odontogenic infections and the responsible bacteria have not been described in detail. METHODS: Search databases (e.g., PubMed, MEDLINE, Web of Science, Embase) for reports published from 2018.1 to 2022.9. Use search strategies: ("odontogenic infections" OR "pulpitis" OR "periapical lesions" OR "periodontal diseases") AND ("disseminated infections" OR "complication"). RESULTS: Fourteen different types of disseminated odontogenic infections, most of which are polymicrobial infections, can spread through the body either direct or through hematogenous diffusion. Multiple microbial infections can be more invasive in the transmission of infection. Secondary infections are commonly associated with bacteria like Fusobacterium spp., Streptococcus spp., Peptostreptococcus spp., Prevotella spp., and Staphylococcus spp. Antibiotics with broad-spectrum activity are fundamental as first-line antimicrobial agents based on the microorganisms isolated from disseminated infections. CONCLUSION: This review elaborates on the epidemiology, microorganisms, risk factors, and dissemination routes, and provides evidence-based opinions on the diagnosis, multidisciplinary management, and prevention of odontogenic infections for dentists and clinicians.

Impact of COVID-19 on patient follow-up during supportive periodontal therapy: a retrospective study based on phone call survey.

BACKGROUND: COVID-19 and the subsequent intermittent lockdown measures from 2020 to 2022 in China critically disrupted regular medical activities, including dental care. This study aimed to investigate the impact of COVID-19 on long-term follow-up at the Stomatology Hospital, Zhejiang University School of Medicine and to evaluate potential causes of loss to follow-up. METHODS: A total of 1062 patients with periodontitis who visited the hospital from January 2019 to June 2022 were included in this study, and patient information was collected retrospectively in the form of a telephone questionnaire. The questionnaire consisted of 19 questions in four areas: demographic characteristics, clinical periodontal parameters, oral hygiene habits, and follow-up-related open-ended questions (specific reasons for loss to follow-up, attitudes toward follow-up and suggestions for increasing participation in future follow-ups). Regression analysis of factors influencing the follow-up of patients with periodontitis were analyzed by regression analysis using R (v4.2.3) software. RESULTS: A total of 536 (50.47%) valid questionnaires were collected from 1062 patients. Personal factors (42.5%), instead of the COVID-19 epidemic (20.0%), were the main factors that impacted the loss to follow-up in long-term periodontal treatment, while work factors (19.8%), hospital factors (16.4%), and transportation or distance factors (14.7%) were all important factors. A family history of periodontitis [odds ratio (OR) = 0.567, 95% confidence interval (CI): 0.393, 0.817, p = 0.002], as well as frequent use of dental devices (OR = 0.540, 95% CI: 0.375, 0.777, p = 0.001), were significantly associated with a "negative" attitude toward follow-up visits. CONCLUSION: This survey suggests that the COVID-19 epidemic factor was an important cause contributed to the loss to follow-up during supportive periodontal therapy (SPT) among a variety of potential factors. Majority of patients had negative attitudes toward subsequent continued participation in supportive care.

Multifocal epithelial hyperplasia confined to the interdental papilla of an adult Chinese man: a rare case report and literature review.

BACKGROUND: Multifocal epithelial hyperplasia (MEH), or focal epithelial hypertension (FEH), or Heck's disease, is an uncommon, benign oral mucosal disease associated with human papillomavirus infection. It is mostly observed in indigenous populations of the world, and has been rarely reported in China. However, previous research suggested there might be a greater prevalence of MEH in the Chinese population. While predominantly involves the lips, buccal mucosa and tongue, MEH was occasionally reported to affect the hard palate and gingiva as well. CASE PRESENTATION: This paper reports a case of extensive MEH lesions that confined to the interdental papilla of a Chinese male without detection of HPV, and summarizes the published gingiva-involved MEH reports from 1966 until present. The lesions were excised with an Er: YAG laser after scaling and root planning, no recurrence was observed after 6-month follow-up. CONCLUSIONS: The present report illustrates the need for clinicians to be aware of rare presentations of MEH to facilitate a prompt diagnosis and proper management. More reports are encouraged to determine a correct prevalence rate of MEH in China.

[Echinacoside hampers malignant progression of breast cancer MCF-7 cells by modulating AKR1B10/ERK signal transduction].

This study analyzes the impact of echinacoside(ECH) in the proliferation, metastasis and adriamycin(ADR) resistance of breast cancer(BC) MCF-7 cells via the modulation of aldo-keto reductase family 1 member 10(AKR1B10)/extracellular signal-regulated kinase(ERK) pathway. The chemical structure of ECH was firstly confirmed. MCF-7 cells were treated with different concentration(0, 10, 20, 40 µg·mL~(-1)) of ECH for 48 h. Western blot was used to analyze expression of AKR1B10/ERK pathway-associated proteins and cell counting kit-8(CCK-8) assay to determine cell viability. MCF-7 cells were collected and classified into control group, ECH group, ECH + Ov-NC group, and ECH + Ov-AKR1B10 group. Then Western blot was employed to analyze the expression of AKR1B10/ERK pathway-associated proteins. CCK-8 and 5-ethynyl-2'-deoxyuridine(EdU) assay were used to examine cell proliferation. Cell migration was appraised with scratch assay, Transwell assay, and Western blot. Eventually, MCF-7 cells were treated with ADR for 48 h to induce ADR resistance. Cell viability was tested by CCK-8 assay and cell apoptosis was estimated based on terminal-deoxynucleoitidyl transferase mediated nick end labeling(TUNEL) assay and Western blot. Based on Protein Data Bank(PDB) and molecular docking, the binding affinity of ECH to AKR1B10 was assessed. Various doses of ECH decreased the expression of AKR1B10/ERK pathway-associated proteins in a dose-dependent manner and declined cell viability compared with the control group. Compared with the control group, 40 µg·mL~(-1) ECH blocked the AKR1B10/ERK pathway in MCF-7 cells and inhibited the proliferation, metastasis and ADR resistance of the cells. Compared with the ECH + Ov-NC group, ECH + Ov-AKR1B10 group showed the recovery of some biological behaviors of MCF-7 cells. ECH also targeted AKR1B10. ECH can inhibit the proliferation, metastasis, and ADR resistance of BC cells by blocking AKR1B10/ERK pathway.

Effects of stellate ganglion block on early brain injury in patients with subarachnoid hemorrhage: a randomised control trial.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a common neurosurgical emergency, and early brain injury (EBI) plays an important role in acute brain injury of SAH. Our objective is to investigate the effect of stellate ganglion block (SGB) on the clinical prognosis of patients with SAH (registration number ChiCTR2000030910). METHODS: A randomized controlled trial was conducted with 102 participants. Patients with SAH were assigned to the SGB or nSGB group. Patients in the SGB group received SGB four times (once every other day starting on the day of the surgery). In contrast, patients in the nSGB group only received standard care. Data were collected on the day before surgery (T0) and on the 1st (T1), 3rd (T2) and 7th day (T3) after surgery. The primary outcomes included EBI markers (including IL-1ß, IL-6, TNF-α, ET-1, NPY, NSE and S100ß), the mean cerebral blood flow velocity of the middle cerebral artery (Vm-MCA) and the basilar artery (Vm-BA). All cases were followed up for 6 months after surgery. RESULTS: The levels of the EBI markers in both groups were higher at T1-T3 than at T0 (P<0.05), and the Vm-MCA and Vm-BA were also increased at the same times. However, the levels of the EBI markers were lower in the SGB group than in the nSGB group (P<0.05), and the increases of Vm-MCA and Vm-BA were also lower (P<0.05). The prognosis score and neurological deficit were better in the SGB group than in the nSGB group (P<0.05). CONCLUSIONS: SGB can improve the prognosis of SAH patients by inhibiting the inflammatory response during EBI and by reducing endothelial dysfunction and relieving CVS. TRIAL REGISTRATION: Clinical trial number: ChiCTR2000030910 ; Registry URL: Chinese Clinical Trial Registry; Principal investigator's name: Ying Nie; Date of Trial registration: March, 2020 (retrospectively registered).

Tumor-associated antigen-based personalized dendritic cell vaccine in solid tumor patients.

Tumor-associated antigens (TAAs) have been tested in various clinical trials in cancer treatment but the patterns of specific T cell response to personalized TAA immunization remains to be fully understood. We report antigen-specific T cell responses in patients immunized with dendritic cell vaccines pulsed with personalized TAA panels. Tumor samples from patients were first analyzed to identify overexpressed TAAs. Autologous DCs were then transfected with pre-manufactured mRNAs encoding the full-length TAAs, overexpressed in the patients' tumors. Patients with glioblastoma multiforme (GBM) or advanced lung cancer received DC vaccines transfected with personalized TAA panels, in combination with low-dose cyclophosphamide, poly I:C, imiquimod and anti-PD-1 antibody. Antigen-specific T cell responses were measured. Safety and efficacy were evaluated. A total of ten patients were treated with DC vaccines transfected with personalized TAA panels containing 3-13 different TAAs. Among the seven patients tested for anti-TAA T cell responses, most of the TAAs induced antigen-specific CD4+ and/or CD8+ T cell responses, regardless of their expression levels in the tumor tissues. No Grade III/IV adverse events were observed among these patients. Furthermore, the treated patients were associated with favorable overall survival when compared to patients who received standard treatment in the same institution. Personalized TAA immunization-induced-specific CD4+ and CD8+ T cell responses without obvious autoimmune adverse events and was associated with favorable overall survival. These results support further studies on DC immunization with personalized TAA panels for combined immunotherapeutic regimens in solid tumor patients.Trial registration ClinicalTrials.gov, NCT02709616 (March, 2016), NCT02808364 (June 2016), NCT02808416 (June, 2016).

[Single-modal neuroimaging computer aided diagnosis for schizophrenia based on ensemble learning using privileged information].

Neuroimaging technologies have been applied to the diagnosis of schizophrenia. In order to improve the performance of the single-modal neuroimaging-based computer-aided diagnosis (CAD) for schizophrenia, an ensemble learning algorithm based on learning using privileged information (LUPI) was proposed in this work. Specifically, the extreme learning machine based auto-encoder (ELM-AE) was first adopted to learn new feature representation for the single-modal neuroimaging data. Random project algorithm was then performed on the learned high-dimensional features to generate several new feature subspaces. After that, multiple feature pairs were built among these subspaces to work as source domain and target domain, respectively, which were used to train multiple support vector machine plus (SVM+) classifier. Finally, a strong classifier is learned by combining these SVM+ classifiers for classification. The proposed algorithm was evaluated on a public schizophrenia neuroimaging dataset, including the data of structural magnetic resonance imaging (sMRI) and functional MRI (fMRI). The results showed that the proposed algorithm achieved the best diagnosis performance. In particular, the classification accuracy, sensitivity and specificity of the proposed algorithm were 72.12% ± 8.20%, 73.50% ± 15.44% and 70.93% ± 12.93%, respectively, on the sMRI data, and it also achieved the classification accuracy of 72.33% ± 8.95%, sensitivity of 68.50% ± 16.58% and specificity of 75.73% ± 16.10% on the fMRI data. The proposed algorithm overcomes the problem that the traditional LUPI methods need the additional privileged information modality as source domain. It can be directly applied to the single-modal data for classification, and also can improve the classification performance. Therefore, it suggests that the proposed algorithm will have wider applications.

The association between chronic periodontitis and vasculogenic erectile dysfunction: a systematic review and meta-analysis.

AIM: The purpose of this systematic review and meta-analysis was to explore the association between erectile dysfunction (ED) and chronic periodontitis (CP) in observational studies. MATERIALS AND METHODS: A literature search of PubMed, EMBASE and Cochrane up to and including May 22, 2015, was conducted by two independent reviewers. Statistical analysis was performed using Review Manager 5.3, and the results are expressed as odds ratios (ORs) together with 95% confidence intervals (CIs), as determined using a random effects model. Subgroup analysis was performed by age. RESULTS: Of the 250 potentially eligible articles, four studies, involving 38,111 cases and 174,807 controls, were included. Based on random effects meta-analysis, a significant association between CP and ED was identified (OR = 3.07, 95% CI: 1.87-5.05, p < 0.001). Sensitivity analysis was performed due to the presence of statistically extensive heterogeneity (I(2) = 98%). CONCLUSIONS: The results of this systematic review revealed a positive association between CP and ED; however, because the presence and extent of statistical heterogeneity limits the conclusiveness of our findings, larger and better-controlled studies of socially homogeneous populations as well as pathophysiological studies are required to confirm the relationship between CP and ED and to explore the biological mechanisms involved.

Small extracellular vesicles derived from lipopolysaccharide-preconditioned dental follicle cells inhibit cell apoptosis and alveolar bone loss in periodontitis.

OBJECTIVE: This study aimed to explore the effects of small extracellular vesicles derived from lipopolysaccharide-preconditioned dental follicle cells (L-D-sEV) on periodontal ligament cells from periodontitis affected teeth (p-PDLCs) in vitro and experimental periodontitis in mice. DESIGN: In vitro, the biological function of p-PDLCs and the underlying molecular mechanism were investigated by flow cytometry, Western blot, and quantitative real-time PCR (qRT-PCR) analysis. Eighteen-eight-week-old male C57BL/6 mice were randomly divided into three groups: control (Con), periodontitis (Peri), and L-D-sEV groups. Mice periodontitis model was induced by placing the 5-0 silk thread (around the maxillary second molar) and P.gingivalis (1 ×107 CFUs per mouse). In vivo, the alveolar bone loss, osteoclast activity, and macrophage polarization were measured by micro-computed tomography and histological analysis. RESULTS: In vitro, the RANKL/OPG ratio and phosphorylation of JNK and P38 protein levels of p-PDLCs were significantly decreased after L-D-sEV administration. Besides, flow cytometry and qRT-PCR analysis showed that L-D-sEV reduced apoptosis of p-PDLCs, down-regulated apoptosis-related genes Caspase-3 and BCL-2-Associated X expression, and up-regulated B-cell lymphoma-2 gene levels. In vivo, L-D-sEV administration significantly reduced alveolar bone loss, inhibited osteoclast activity, and induced M2 polarization. The histological analysis showed that iNOS/CD206, RANKL/OPG, p-JNK/JNK, and p-P38/P38 ratios were significantly lower in the L-D-sEV group than in the Peri group. CONCLUSIONS: L-D-sEV administration alleviated alveolar bone loss by mediating RANKL/OPG-related osteoclast activity and M2 macrophage polarization, alleviating p-PDLCs apoptosis and proliferation via the JNK and P38 pathways.

Advances in Cancer Nanovaccines: Harnessing Nanotechnology for Broadening Cancer Immune Response.

Many advances have been made recently in the field of cancer immunotherapy, particularly with the development of treatments such as immune checkpoint inhibitors and adoptive cellular immunotherapy. The efficacy of immunotherapy is limited, however, owing to high levels of tumor heterogeneity and the immunosuppressive environments of advanced malignant tumors. Therefore, therapeutic anticancer vaccines have gradually become powerful tools for inducing valid antitumor immune responses and regulating the immune microenvironment. Tumor vaccines loaded in nanocarriers have become an indispensable delivery platform for tumor treatment because of their enhanced stability, targeting capability, and high level of safety. Through a unique design, cancer nanovaccines activate innate immunity and tumor-specific immunity simultaneously. For example, the design of cancer vaccines can incorporate strategies such as enhancing the stability and targeting of tumor antigens, combining effective adjuvants, cytokines, and immune microenvironment regulators, and promoting the maturation and cross-presentation of antigen-presenting cells (APCs). In this review, we discuss the design and preparation of nanovaccines for remodeling tumor antigen immunogenicity and regulating the immunosuppressive microenvironment.

A Robust Squarate-Cobalt Metal-Organic Framework for CO2/N2 Separation.

The separation of CO2 from the industrial post-combustion flue gas is of great importance to reduce the increasingly serious greenhouse effect, yet highly challenging due to the extremely high stability, low cost, and high separation performance requirements for adsorbents under the practical operating conditions. Herein, we report a robust squarate-cobalt metal-organic framework (MOF), FJUT-3, featuring an ultra-small 1D square channel decorated with -OH groups, for CO2/N2 separation. Remarkably, FJUT-3 not only has excellent stability under harsh chemical conditions but also presents low-cost property for scale-up synthesis. Moreover, FJUT-3 shows excellent CO2 separation performance under various humid and temperature conditions confirmed by the transient breakthrough experiments, thus enabling FJUT-3 with adequate potentials for industrial CO2 capture and removal. The distinct CO2 adsorption mechanism is well elucidated by theoretical calculations, in which the hierarchical C···OCO2, C-O···CCO2, and O-H···OCO2 interactions play a vital synergistic role in the selective CO2 adsorption process.

A highly efficient needle-free-injection delivery system for mRNA-LNP vaccination against SARS-CoV-2.

Despite the various vaccines that have been developed to combat the coronavirus disease 2019 (COVID-19) pandemic, the persistent and unpredictable mutations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require innovative and unremitting solutions to cope with the resultant immune evasion and establish a sustainable immune barrier. Here we introduce a vaccine-delivery system with a combination of a needle-free injection (NFI) device and a SARS-CoV-2-Spike-specific mRNA-Lipid Nanoparticle (LNP) vaccine. The benefits are duller pain and a significant increase of immunogenicity compared to the canonical needle injection (NI). From physicochemical and bioactivity analyses, the structure of the mRNA-LNP maintains stability upon NFI, contradictory to the belief that LNPs are inclined towards destruction under the high-pressure conditions of NFI. Moreover, mRNA-LNP vaccine delivered by NFI induces significantly more binding and neutralizing antibodies against SARS-CoV-2 variants than the same vaccine delivered by NI. Heterogeneous vaccination of BA.5-LNP vaccine with NFI enhanced the generation of neutralizing antibodies against Omicron BA.5 variants in rabbits previously vaccinated with non-BA.5-specific mRNA-LNP or other COVID-19 vaccines. NFI parameters can be adjusted to deliver mRNA-LNP subcutaneously or intramuscularly. Taken together, our results suggest that NFI-based mRNA-LNP vaccination is an effective substitute for the traditional NI-based mRNA-LNP vaccination.

Combination immunotherapy of glioblastoma with dendritic cell cancer vaccines, anti-PD-1 and poly I:C.

Glioblastoma (GBM) is a lethal cancer with limited therapeutic options. Dendritic cell (DC)-based cancer vaccines provide a promising approach for GBM treatment. Clinical studies suggest that other immunotherapeutic agents may be combined with DC vaccines to further enhance antitumor activity. Here, we report a GBM case with combination immunotherapy consisting of DC vaccines, anti-programmed death-1 (anti-PD-1) and poly I:C as well as the chemotherapeutic agent cyclophosphamide that was integrated with standard chemoradiation therapy, and the patient remained disease-free for 69 months. The patient received DC vaccines loaded with multiple forms of tumor antigens, including mRNA-tumor associated antigens (TAA), mRNA-neoantigens, and hypochlorous acid (HOCl)-oxidized tumor lysates. Furthermore, mRNA-TAAs were modified with a novel TriVac technology that fuses TAAs with a destabilization domain and inserts TAAs into full-length lysosomal associated membrane protein-1 to enhance major histocompatibility complex (MHC) class I and II antigen presentation. The treatment consisted of 42 DC cancer vaccine infusions, 26 anti-PD-1 antibody nivolumab administrations and 126 poly I:C injections for DC infusions. The patient also received 28 doses of cyclophosphamide for depletion of regulatory T cells. No immunotherapy-related adverse events were observed during the treatment. Robust antitumor CD4+ and CD8+ T-cell responses were detected. The patient remains free of disease progression. This is the first case report on the combination of the above three agents to treat glioblastoma patients. Our results suggest that integrated combination immunotherapy is safe and feasible for long-term treatment in this patient. A large-scale trial to validate these findings is warranted.

Enhancement of Green Tires Performance through Ultrasound-Assisted Mixing.

Combined with the traditional internal mixing process, a custom-built ultrasonic generator was introduced in this study. The effect of ultrasonic parameters on the comprehensive performance of tread rubber formulations was investigated. Compared to the traditional mixing process without ultrasonic wave loading, the introduction of ultrasonic enhanced the dispersion and distribution of composite particles in the rubber matrix and improved the overall performance of rubber products. The devil's triangle relationship among the rolling resistance, wet skid resistance, and abrasion resistance of tires was improved. When the wet skid resistance was slightly lost, the rolling resistance and wear rate were effectively reduced. This study provides new insights into a strategy for optimizing the mixing process of the traditional internal mixer, reducing vehicle emissions, extending the service life of tires, and promoting the development of green tires.

Theoretical study of electronic and nonlinear optical properties of novel graphenylene-based materials with donor-acceptor frameworks.

A new functionalized graphenylene-based structure was designed by adsorbing of alkali metals M3 and superalkali M3O (M = Li, Na, K) on graphenylene (BPC) surface. The spectral data show that the spectral properties of the M3O@BPC system are very similar because the two-dimensional material plays a major role in the main transition. However, for M3@BPC system, the spectral shapes of the three systems show significant changes compared to each other because the different alkali metals play a major role in the main transition process. The calculation results show that the introduction of superalkali does not significantly increase the first polarizability; however, the introduction of alkali metals can obtain considerable nonlinear optical materials. For M3@BPC system, the first hyperpolarizability increases significantly when heavier alkali metal is introduced into the two-dimensional structure, which is found to be 866,290.9 au for K3@ BPC. A two-level model and first hyperpolarizability density can explain the large first polarizability of these systems.

Polypyrrole Decorated Flower-like and Rod-like ZnO Composites with Improved Microwave Absorption Performance.

In this study, zinc oxide (ZnO)/polypyrrole (PPy) composites with flower- and rod-like structures were successfully fabricated by in situ polymerization and the hydrothermal method and used as microwave absorption (MWA) materials. The surface morphologies, crystal structures, and electromagnetic features of the as-prepared samples were measured by field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and vector network analyzer (VNA). The results show that the conductive polymer PPy was successfully decorated on the surface of ZnO substrates. The MWA ability of flower- and rod-like ZnO/PPy composites is significantly enhanced after introduction of PPy. Rod-like ZnO/PPy composites exhibited superior MWA properties than those of flower-like ZnO/PPy. The former achieved a minimum reflection loss (RLmin) of −59.7 dB at 15.8 GHz with a thickness of 2.7 mm, and the effective absorption bandwidth (EAB, RL < −10 dB) covered 6.4 GHz. PPy addition and stacked structure of rod-like ZnO/PPy composites can effectively improve the dielectric properties, form multiple reflections of incident electromagnetic waves, and generate an interfacial polarization effect, resulting in improved MWA properties of composite materials.