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1.
IDCases ; 36: e01937, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38601430

RESUMO

Brucellosis (undulant fever) is a zoonotic infection caused by Brucella species. It typically presents with fever, malaise, night sweats, and arthralgia. One of its rare complications is infective endocarditis, which occurs in approximately 1.3% of patients and can be further complicated by embolic stroke. This report describes a rare occurrence of Brucella endocarditis presenting as an embolic stroke. A 34-year-old male presented with sudden left-sided weakness and fever. He reported headaches, fever, and generalized weakness in the preceding week. The patient worked on a farm and hence had animal contact. A neurological exam showed left-sided facial weakness, and power of 0/5 and 1/5 in the left upper and lower extremities, respectively. CT scan of the head revealed a right middle cerebral artery (MCA) territory infarct with penumbra and a right MCA occlusion. He underwent a cerebral artery thrombectomy with successful recanalization. However, he continued to have fever and high inflammatory markers. Echocardiography showed aortic valve vegetation and blood cultures grew Brucella melitensis. A multidisciplinary meeting was held to determine the optimal management, which included a course of rifampicin and doxycycline.

2.
Saudi Dent J ; 36(2): 328-333, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38419996

RESUMO

Objectives: We aimed to compare treatment outcomes of periodontal supra-bony defects using single flap (SFA) plus concentrate growth factor versus SFA alone. Methods: 32 supra-bony periodontal defects were randomly assigned to test and control groups. Outcome variables were clinical attachment level (primary outcome). Probing pocket depths, gingival recessions, bone gain, post-surgical pain using visual analogue scale and wound healing index were recorded as secondary outcomes. Clinical and radiographic assessments were recorded at baseline and 6 months after treatment, whereas pain score and wound healing index were recorded within 10 days after surgery. Results: Test group showed a significant improvement in all tested parameters compared to control group (P-value ≤ 0.05). Better patient centered outcomes (wound healing and pain scores) were highly achieved in the test group compared to controls. Conclusion: The tested combined approach offers better periodontal and patient centered treatment outcomes in management of periodontal supra-bony defects.

3.
Endocrinol Diabetes Metab ; 7(2): e00471, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38411039

RESUMO

INTRODUCTION: Insulin-like growth factor-2 (IGF-2)-mediated hypoglycemia is a rare yet clinically significant entity with considerable morbidity and mortality. Existing literature is limited and fails to offer a comprehensive understanding of its clinical trajectory, management and prognostication. METHODS: Systematic review of English-language articles reporting primary patient data on IMH was searched using electronic databases (PubMed, Scopus and Embase) from any date up to 21 December 2022. Data were analysed in STATA-16. RESULTS: The systematic review contains 172 studies, including 1 Randomised controlled trial, 1 prospective observational study, 5 retrospective observational studies, 150 case reports, 11 case series and 4 conference abstracts. A total of 233 patients were analysed, averaging 60.6 ± 17.1 years in age, with comparable proportions of males and females. The commonest tumours associated with Insulin-like Growth Factor-2-mediated hypoglycaemia were fibrous tumours (N = 124, 53.2%), followed by non-fibrous tumours originating from the liver (N = 21, 9%), hemangiopericytomas (N = 20, 8.5%) and mesotheliomas (N = 11, 4.7%). Hypoglycaemia was the presenting feature of NICT in 42% of cases. Predominant clinical features included loss of consciousness (26.7%) and confusion (21%). The mean IGF-2 and IGF-1 levels were 882.3 ± 630.6 ng/dL and 41.8 ± 47.8, respectively, with no significant correlation between these levels and patient outcomes. Surgical removal was the most employed treatment modality (47.2%), followed by medication therapy. The recovery rate was 77%, with chronic liver disease (CLD) significantly associated with a poor outcome (OR: 7.23, P: 0.03). Tumours originating from fibrous tissues were significantly associated with recovery (p < .001). In the logistic regression model, CLD remained a significant predictor of poor outcomes. CONCLUSION: This systematic review highlights that most non-islet-cell tumour-hypoglycaemia (NICTH) is due to fibrous tumours. NICTs demonstrate a variable prognosis, which is fair if originating from fibrous tissue. Management such as octreotide, corticosteroids, diazoxide, embolization, radiotherapy and surgical resection have disparate success rates.


Assuntos
Hipoglicemia , Fator de Crescimento Insulin-Like II , Masculino , Feminino , Humanos , Fator de Crescimento Insulin-Like II/análise , Peptídeos Semelhantes à Insulina , Estudos Retrospectivos , Hipoglicemia/etiologia , Estudos Observacionais como Assunto
4.
Saudi Dent J ; 36(1): 151-157, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38375393

RESUMO

Objectives: This study aimed to assess the effectiveness of ridge preservation using a polycaprolactone (PCL) scaffold combined with platelet-rich fibrin (PRF) to promote bone regeneration before implantation. Materials and Methods: This prospective study was conducted at Al-Azhar University in Egypt. It included 30 participants requiring the extraction of their last mandibular premolar before constructing an implant-supported overdenture. The participants were divided into three groups: Group A was treated with a PCL scaffold and PRF as ridge preservative materials, Group B was treated with PRF alone, and Group C (control) was treated with no preservative material. Bone samples were collected for histomorphometric analysis at implant placement. Results: The participants' mean age was 65.3 ± 4.27 years, and 18 (60%) were male. Postoperative alveolar bone lengths differed significantly between Groups A and B (P = 0.001). However, alveolar bone width changes did not differ significantly among groups. In contrast, the postoperative bone density and loss differed significantly among groups (P = 0.001). Conclusion: Combining two ridge preservation techniques (PCL and PRF) enhanced participants' alveolar bone remodelling by decreasing its resorption and maintaining its width.

5.
Cureus ; 16(1): e51725, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38318560

RESUMO

Malignant peritoneal mesothelioma (MPM) is a rare subtype of mesothelioma. There are three main histological subtypes of mesothelioma: epithelioid, sarcomatoid, and biphasic (mixed). Risk factors include asbestos exposure, previous radiation, and some germline mutations. Treatment includes surgical resection of amenable tumors or cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. We present a 34-year-old male who presented with weight loss, night sweats, and pleuritic chest pain and was found to have ascites with peritoneal nodularity on abdominal imaging. He had a history of tuberculosis contact, but no history of asbestos exposure. After a long challenging and interesting diagnostic process, he was subsequently diagnosed with biphasic MPM. The diagnostic challenge stems from not only the rarity of the tumor but also from the absence of risk factors, the unavailability of some special laboratory investigations, in addition to the potentially misleading effect of tuberculosis exposure history, a top differential diagnosis in the case. This is a case report of a really challenging and totally unexpected diagnosis of biphasic peritoneal mesothelioma in a patient with tuberculosis exposure, constitutional symptoms, but no history of asbestos exposure. It highlights the diagnostic process as well as the importance of early diagnosis to improve the overall survival of such malignancies.

6.
Sci Rep ; 13(1): 21923, 2023 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-38081941

RESUMO

Plant-parasitic nematodes (PPNs) are vital soil organisms well-known to damage and reduce crop yield worldwide. Surveys were attempts to determine the impact of weed species on the communities and composition of nematodes in barley, wheat, quinoa, eggplant, and tomato crops in Alexandria and Ismailia regions of Egypt. During the surveys, eight occurring genera of nematodes were found namely; Meloidogyne spp, Pratylenchus spp, Helicotylenchus spp, Rotylenchulus spp, Xiphinema spp, Criconemoides spp, Ditylenchus spp, and Longidorus spp associated with the soil's rhizosphere of 28 weed species belonging to 12 families. Among these weeds, Hordeum marinum and Sonchus oleraceus were good hosts to nematode species. Both wheat and barley had higher nematode diversity than quinoa in the winter season. Pratylenchus spp, Meloidogyne spp and Rotylenchulus spp can be considered vital potential PPNs with economic importance. Nematode abundances and structural indices varied greatly based on the host weed species, crop types and soil characteristics. A positive correlation was monitored among weeds, nematode frequencies and relative abundances as well as their crops. Finally, weed species are critical components in nematode communities that may increase the incidence and severity of nematode risks based on crop type and soil characteristics. Therefore weeds should be managed properly to diminish reservoir sites when developing nematode management options.


Assuntos
Hordeum , Abuso de Maconha , Rabditídios , Tylenchida , Tylenchoidea , Humanos , Animais , Plantas Daninhas , Produtos Agrícolas , Pesquisadores , Solo
7.
Comput Biol Med ; 167: 107679, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37976826

RESUMO

We present a novel Pharmacokinetic/Pharmacodynamic (PK/PD) model for the induction phase of anesthesia, incorporating the ψ-Caputo fractional derivative. By employing the Picard iterative process, we derive a solution for a nonhomogeneous ψ-Caputo fractional system to characterize the dynamical behavior of the drugs distribution within a patient's body during the anesthesia process. To explore the dynamics of the fractional anesthesia model, we perform numerical analysis on solutions involving various functions of ψ and fractional orders. All numerical simulations are conducted using the MATLAB computing environment. Our results suggest that the ψ functions and the fractional order of differentiation have an important role in the modeling of individual-specific characteristics, taking into account the complex interplay between drug concentration and its effect on the human body. This innovative model serves to advance the understanding of personalized drug responses during anesthesia, paving the way for more precise and tailored approaches to anesthetic drug administration.


Assuntos
Anestesia , Farmacocinética , Humanos , Simulação por Computador
8.
Case Rep Oncol ; 16(1): 759-764, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37933317

RESUMO

A 78-year-old male patient presented with dyspnea, loss of appetite, and weight loss. Workup and imaging showed suspected malignant lung lesion. Biopsy was done and showed features of pulmonary enteric adenocarcinoma (PEAC). This is a very rare disease and its diagnosis is challenging.

9.
Cureus ; 15(9): e45358, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37849579

RESUMO

Endomyocardial fibrosis (EMF) is a rare restrictive cardiomyopathy in non-tropical areas. It is seen in most of the patients living in or coming from tropical areas, and is rarely seen in patients who have never visited these areas. It is characterized by fibrotic thickening of the endocardium, predominantly affecting the ventricular apices and inflow tracts. Although thrombus formation is a known complication in various cardiac conditions such as atrial fibrillation, atrial flutter, ventricular heart disease, and patent foramen ovale, the occurrence of bilateral thrombus in EMF is exceptionally rare. We present a case report describing a unique finding of bilateral ventricular thrombus in a patient diagnosed with EMF, highlighting the clinical presentation, diagnostic approach, and management challenges associated with this rare phenomenon.

10.
Cureus ; 15(9): e45418, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37854757

RESUMO

Neuroschistosomiasis is a rare manifestation of schistosomal infections presenting with cerebral and spinal cord involvement. We reported a case of a 31-year-old woman who presented with a history of headache, dizziness, and nausea. Brain MRI with contrast showed features suggestive of brain lesion with edema, and a serology test for Schistosoma was positive. She was diagnosed with neuroschistosomiasis and treated with intravenous steroids followed by praziquantel resulting in a significant regression of the brain mass. Cerebral neuroschistosomiasis is a rare complication of Schistosoma infection, and clinicians should consider it among the differential diagnosis of unexplained brain lesions.

11.
Environ Monit Assess ; 195(11): 1357, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37870616

RESUMO

Heavy metals are considered the most common pollutants in industrial wastewater areas. Out of thirty bacterial isolates, only 3 isolates sighted the highest metal resistance activity for Zn+2, Fe+2, Pb+2, Co+2, Mn+2, Ni+2, and Cd+2. The biochemical and DNA homology identification with similarities 99.58%, 99.79%, and 99.86% of those isolates was identified and deposited in WDCM, respectively, as Enterobacter kobei OM144907 SCUF0000311, Enterobacter cloacae OM180597 SCUF0000312, and Enterobacter hormaechei OM181067 SCUF0000313. The minimum tolerance activity (MIC) of heavy metal concentrations against E. kobei and E. cloacae was 25, 15, and 15 mmol/l for Ni+2, Fe+2, and Mn+2, respectively, and 10 mmol/l for Zn+2, Pb+2, Co+2, and Cd+2, while against E. hormaechei, it is 15 mmol/l for Ni+2, Fe+2, and Mn+2 and 10 mmol/l for Zn+2, Pb+2, Co+2, and Cd+2. The consortium and solitary application of bacterial isolates towards heavy metal removal at 100%, 200%, and 300% industrial wastewater concentrations were conducted and showed that more than 90% removal of Zn+2, Fe+2, Pb+2, Mn+2, Ni+2, and Cd+2 from a non-concentrated polluted sample (100%) was reported by the three strains. With doubling the polluted sample concentration (200%), the highest removal efficiency for Zn+2, Pb+2, Mn+2, Ni+2, and Cd+2 was reported by E. cloacae as 70. 75, 66, 65, and 57%, respectively. Removal efficiency after increasing the polluted sample concentration to 300% showed that E. cloacae removed above 45% of all tested heavy metals except Pb+2. Ultimately, E. cloacae exposed the highest efficiency with recommendations for heavy metals removal under higher concentrations.


Assuntos
Metais Pesados , Águas Residuárias , Biodegradação Ambiental , Cádmio , Chumbo , Monitoramento Ambiental , Metais Pesados/análise , Enterobacter , Resíduos Industriais
12.
ATS Sch ; 4(3): 362-371, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37795120

RESUMO

Background: Mechanical ventilation (MV) management is an essential skill for pulmonary and critical care medicine (PCCM) fellows to master during training. The unprecedented emergence of the coronavirus disease (COVID-19) pandemic highlighted the need for advanced operator competency in MV to improve patients' outcomes. Objective: We aimed to create a standardized case-based curriculum using a blended approach of high-fidelity simulation, rapid-cycle deliberate practice, video didactics, and hands-on small group sessions for rapid accumulation of knowledge and hands-on skills for PCCM fellows before caring for critically ill patients during the COVID-19 pandemic. Methods: The MV curriculum consisted of the following steps: 1) baseline written knowledge test with 15 multiple-choice questions covering MV, the latest evidence-based practices, and pathophysiology of COVID-19; 2) baseline confidence survey using a 5-point Likert scale; 3) a one-on-one session using a high-fidelity simulation manikin, a lung simulator, and a mechanical ventilator to test baseline competencies; 4) a structured debriefing tailored per fellow's 50-point competency assessment checklist from the simulation using rapid-cycle deliberate practice; 5) video didactics; 6) a hands-on session in small groups for basic knobology, waveforms, and modes of MV; 7) a one-on-one simulation reassessment session; 8) a written knowledge posttest; and 9) a post-training confidence survey using a 5-point Likert scale. Results: Eight PCCM fellows completed the training. The mean multiple-choice question score increased from 7.4 ± 2.9 to 10.4 ± 2.4 (P < 0.05), and the simulation scores increased from 17.1 ± 4.4 to 30.8 ± 3.7 (P < 0.05). Comparing the simulation reassessment to the baseline, fellows showed significant improvement (P < 0.05) in assessing indications for MV; implementing rapid sequence intubation for patients with COVID-19; initiating MV and ventilator bundle per best practices; recognizing and managing mucous plugging, ventilator dyssynchrony, and evidence-based treatments for acute respiratory distress syndrome; and developing a care plan for proning. The post-training survey revealed improved learner confidence in all competencies. Conclusion: This pilot MV curriculum using a blended approach was feasible and allowed PCCM fellows to significantly improve their knowledge and hands-on skills, allowing for the appropriate use of MV during the pandemic. Self-reported improvement scores further reinforced this. The emergent need for novice learners may again be necessary for future pandemic settings where standard training models requiring extensive training time are limited.

13.
Hematology ; 28(1): 2252651, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37664905

RESUMO

BACKGROUND: Cold agglutinin disease (CAD) is immune-mediated hemolytic anemia. The disease is caused by cold reactive autoantibodies that induce hemolysis through the activation of the complement pathway. Most patients with CAD are elderly, and half may have refractory CAD that may not respond to the first-line treatment option (i.e. rituximab). Some cases are refractory to multiple lines of therapy, including chemotherapeutic agents, which might be toxic, especially for elderly patients. Daratumumab is a human monoclonal antibody targeting CD 38 glycoprotein, a transmembrane protein highly expressed in lymphoid and plasma cells. Daratumumab is currently approved for treating multiple myeloma and is used mainly as a combination therapy with other agents. CASE PRESENTATION: Our patient is a 69-year-old female diagnosed with CAD after presenting with severe anemia and significant circulatory symptoms. Rituximab was not effective in controlling her disease, and she refused other available chemotherapeutic agents due to their side effects profile. We used daratumumab combined with erythropoietin, which led to a dramatic response measured by stabilizing her hemoglobin levels and transfusion independence. CONCLUSION: Our case is the third reported case of refractory CAD successfully treated with daratumumab, which suggests that daratumumab might be a potential agent for the treatment and control of refractory Cold Agglutinin Disease.


Assuntos
Anemia Hemolítica Autoimune , Idoso , Feminino , Humanos , Anemia Hemolítica Autoimune/tratamento farmacológico , Anticorpos Monoclonais/uso terapêutico , Rituximab/uso terapêutico , Terapia Combinada
14.
Sci Rep ; 13(1): 15993, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37749115

RESUMO

From raw material extraction to final product disposal, the construction industry is integrally involved in every stage of the greenhouse gas emissions life cycle. One of the main causes of the climate catastrophe is the increasing use of polluting energy sources to power our homes and businesses. This massive problem of global warming has now forced countries to act. To further address sustainability, they seek to reduce energy consumption and CO2 emissions by adopting more sustainable materials. The current trend in scientific research is to use waste resources to improve the properties of various materials to exacerbate the problems of climate change because of the use of traditional building materials. Therefore, one of the most environmentally friendly alternatives to the standard procedure is the use of agricultural residues to improve the quality of building materials. This improvement will modify the thermal properties of building materials such as bricks, which will lead to an improvement in energy efficiency inside buildings, especially residential buildings. As a result, the research focused solely on simulating several bio-brick alternatives that had been discovered in earlier studies in order to test their viability in terms of increasing the energy efficiency of residential buildings in one of the hot cities. The study demonstrated that using bio-building materials can lower energy usage. In addition to saving energy in residential constructions, rice straw cement bricks and sugarcane bricks have operating efficiency rates of roughly 7% and 12%, respectively. All these advancements over conventional brick reduce greenhouse gas emissions and carbon dioxide.

15.
Cureus ; 15(8): e43128, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37692615

RESUMO

Adult-onset Still's disease (AOSD) is a rare systemic inflammatory disease that involves the excessive production of proinflammatory cytokines. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening immune-mediated disorder that can be primary or secondary to malignancy, infections, and autoimmune diseases. We present an interesting case of a young female with adult-onset Still's disease that commenced during pregnancy. Whole-body fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) scan showed diffuse uptake in the spleen and bone marrow with widespread lymphadenopathy. During the delayed diagnostic process to exclude lymphoproliferative malignancy, she developed severe HLH/macrophage activation syndrome (MAS) with multiorgan failure. In this case report, we described the challenges faced during the diagnosis of AOSD. We also highlighted the importance of using clinical criteria to aid in the early diagnosis and management of AOSD patients and the role of FDG-PET/CT scans in patients with AOSD. Additionally, we discussed the management aspects for patients with macrophage activation syndrome.

16.
Cureus ; 15(8): e43493, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37719556

RESUMO

Tuberculous septic arthritis is a rare type of septic arthritis that is caused by Mycobacterium tuberculosis. However, it can lead to devastating complications if not diagnosed and treated correctly. We hereby report a 41-year-old female with no medical history who presented with a three-week history of right hip pain and inability to bear weight, found to have moderate to severe tenderness at the right anterior hip and gluteal area and limitation of joint movement. Magnetic resonance imaging (MRI) of the hip showed features of right hip septic arthritis with synovitis and anteromedial and posteromedial small collections. She was diagnosed with tuberculosis (TB) after joint fluid aspiration, and she was started on anti-TB treatment including isoniazid, rifampicin, ethambutol, and pyrazinamide directly after. Considering the case and the subacute presentation that can mimic bacterial septic arthritis, clinicians should always consider TB infection in their differential diagnosis upon assessing a suspected patient with septic arthritis even with a subacute presentation to achieve the correct diagnosis and start appropriate treatment to avoid its harmful complications.

17.
PeerJ Comput Sci ; 9: e1180, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37547391

RESUMO

Background: The development of sequencing technology increases the number of genomes being sequenced. However, obtaining a quality genome sequence remains a challenge in genome assembly by assembling a massive number of short strings (reads) with the presence of repetitive sequences (repeats). Computer algorithms for genome assembly construct the entire genome from reads in two approaches. The de novo approach concatenates the reads based on the exact match between their suffix-prefix (overlapping). Reference-guided approach orders the reads based on their offsets in a well-known reference genome (reads alignment). The presence of repeats extends the technical ambiguity, making the algorithm unable to distinguish the reads resulting in misassembly and affecting the assembly approach accuracy. On the other hand, the massive number of reads causes a big assembly performance challenge. Method: The repeat identification method was introduced for misassembly by prior identification of repetitive sequences, creating a repeat knowledge base to reduce ambiguity during the assembly process, thus enhancing the accuracy of the assembled genome. Also, hybridization between assembly approaches resulted in a lower misassembly degree with the aid of the reference genome. The assembly performance is optimized through data structure indexing and parallelization. This article's primary aim and contribution are to support the researchers through an extensive review to ease other researchers' search for genome assembly studies. The study also, highlighted the most recent developments and limitations in genome assembly accuracy and performance optimization. Results: Our findings show the limitations of the repeat identification methods available, which only allow to detect of specific lengths of the repeat, and may not perform well when various types of repeats are present in a genome. We also found that most of the hybrid assembly approaches, either starting with de novo or reference-guided, have some limitations in handling repetitive sequences as it is more computationally costly and time intensive. Although the hybrid approach was found to outperform individual assembly approaches, optimizing its performance remains a challenge. Also, the usage of parallelization in overlapping and reads alignment for genome assembly is yet to be fully implemented in the hybrid assembly approach. Conclusion: We suggest combining multiple repeat identification methods to enhance the accuracy of identifying the repeats as an initial step to the hybrid assembly approach and combining genome indexing with parallelization for better optimization of its performance.

18.
Heliyon ; 9(1): e12757, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36685395

RESUMO

Plant invasive success is attributed to invaders' ecological advantages over their native neighbors. However, increasing evidence suggests that these advantages are expected to attenuate over time because of natural enemy accumulation, ecological evolution of native species and autotoxicity. We determined how an invasive Ageratina adenophora could remain its competitive advantages over time by avoiding its autotoxicity. Our results highlighted that the autotoxicity of A. adenophora in its invaded soil was reduced by some microbes. Moreover, an autotoxic allelochemical, 2-coumaric acid glucoside, detected in the invaded soil, demonstrated distinctly autotoxic effects on its seed germination and seedling growth. However, the autotoxic effects were greatly alleviated by a bacterium Bacillus cereus, accumulated by A. adenophora. Furthermore, the allelochemical could be almost completely degraded by B. cereus within 96 h. Accordingly, we speculate that A. adenophora could aggregate B. cereus to release its autotoxicity maintaining its competitive advantages over time.

19.
PLoS One ; 18(1): e0280866, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36689420

RESUMO

Allelopathy has been considered a good explanation for the successful invasion of some invasive plants. However, the real latitudinal and longitudinal allelopathic effects on native species have rarely been documented since many exotics have spread widely. We conducted a Petri dish experiment to determine the latitudinal and longitudinal allelopathic patterns of an invasive alligator weed (Alternanthera philoxeroides) on a common crop (Lactuca sativa) in China, and find what determines the allelopathic intensity. The results showed that the allelopathic effects of A. philoxeroides increased with the latitude while decreased with the longitude. This indicated that A. philoxeroides used its allelopathy to gain competitive advantages more in its recent invaded communities than that in its early invaded ones as A. philoxeroides is expanding from southeast China to northwest China. Furthermore, we found that the allelopathic intensity of A. philoxeroide was negatively correlated to the leaf contents of soluble carbohydrate (SC), carbon (C) and nitrogen (N), but that was positively correlated to the leaf contents of soluble protein (SP), free amino acids (FAA), plant polyphenol (PP), phosphorus (P) and potassium (K). These results suggested that the allelopathic intensity of A. philoxeroide was more determined by the limited P and K nutrients as well as the intermediate allelochemicals (SP, FAA, PP) rather than the unlimited C, N and SC. Thus, we can speculate that the negative or positive effects of plant aqueous extracts are a function of not only the extract concentrations but also the trade-offs between inhibition and promotion of all components in the extracts. Then we could reduce the allelopathic effects of A. philoxeroide by controlling the component contents in the plant tissues, by fertilization or other managements, especially in the plant recent invaded communities.


Assuntos
Jacarés e Crocodilos , Amaranthaceae , Animais , Plantas Daninhas , Espécies Introduzidas , Alelopatia , China , Extratos Vegetais
20.
Indian J Dent Res ; 34(4): 422-426, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38739825

RESUMO

BACKGROUND: The bond strength of an endodontic sealer to the root dentin is an important factor in maintaining the integrity of the root canal seal. The present study aimed to assess the push-out bond strength of three endodontic sealers used with the single-cone obturation technique. MATERIALS AND METHODS: The root canals of 40 central maxillary incisors were instrumented using ProTaper Universal NiTi rotary files. The roots were divided into 4 groups (N = 10) according to the type of root canal sealers: Group 1 (control group): AH Plus/Gutta-percha lateral condensation technique (LC); Group 2: AH Plus/Gutta-percha single-cone technique (SC); Group 3: GuttaFlow 2/SC; Group 4: Realseal SE/SC. After obturation, each tooth was prepared for push-out assessment. The total and sectional push-out bond strengths were measured and statistically analysed. Furthermore, failure modes were identified microscopically. RESULTS: The results indicated that samples in the first group showed the highest total and sectional bond strengths. Samples from other groups showed statistically similar total bond strengths. The highest sectional bond strength was found mainly in the apical root sections. Cohesive failure was predominant for the first group, whereas adhesive failure was predominant in the other groups. CONCLUSIONS: It could be concluded that the dentin bond strengths of the tested sealers used with the single-cone technique were nearly similar but lower than those of AH Plus/LC. The highest sectional bond strength was observed in the apical thirds. The failure mode was mostly cohesive for AH Plus/LC and adhesive for sealers used with the single-cone obturation technique.


Assuntos
Colagem Dentária , Análise do Estresse Dentário , Dentina , Combinação de Medicamentos , Resinas Epóxi , Guta-Percha , Teste de Materiais , Materiais Restauradores do Canal Radicular , Obturação do Canal Radicular , Preparo de Canal Radicular , Materiais Restauradores do Canal Radicular/química , Humanos , Colagem Dentária/métodos , Resinas Epóxi/química , Guta-Percha/química , Obturação do Canal Radicular/métodos , Preparo de Canal Radicular/métodos , Estresse Mecânico , Cavidade Pulpar , Incisivo , Dimetilpolisiloxanos/química , Resinas Compostas/química , Propriedades de Superfície , Titânio/química , Níquel/química
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