Prognostic value of inflammation-related biomarkers in patients with gastroenteropancreatic neuroendocrine neoplasms: A systematic review and meta-analysis

Hematological indicators of chronic systemic inflammation are significant biomarkers for gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). We performed a systematic review and meta-analysis to assess the impact of certain factors on the overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) of patients with GEP-NENs. These factors include the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), and C-reactive protein (CRP) levels. After searching the Medline, Embase, and Cochrane Library databases from January 1, 2000 to October 20, 2022 and the American Society of Clinical Oncology conference proceedings from January 1, 2017, hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted. Subgroup analyses were conducted to identify the origins of heterogeneity and examine the impact of factor grouping. The effects of the cut-off values and sample size were assessed by meta-regression. The results revealed that higher NLRs, PLRs, and CRP levels were associated with shorter OS (HR = 2.09, 95% CI = 1.55-2.8; HR = 1.79, 95% CI = 1.40-2.28; and HR = 2.88, 95% CI = 2.09-3.95, respectively; all p < 0.001). Higher NLRs and lower LMRs were associated with shorter DFS (HR = 3.34, 95% CI = 2.11-5.29 and HR = 2.71, 95% CI = 2.27-3.24, respectively; both p < 0.001). Higher PLRs and CRP levels were correlated with shorter PFS (HR = 3.48, 95% CI = 1.34-9.03, p = 0.01 and HR = 3.14, 95% CI = 1.63-6.08, p = 0.001). As demonstrated in the research, hematological indicators of systemic inflammation are promising biomarkers for GEP-NEN assessment.

Exploring the Role of Gut-Lung Interactions in COPD Pathogenesis: A Comprehensive Review on Microbiota Characteristics and Inflammation Modulation

Chronic obstructive pulmonary disease (COPD) is a paramount contributor to global morbidity and mortality. Over the past decade, the concept of the "gut-lung axis" has emerged, offering a lens through which to examine the intricate interplay between the host, microbiome, and respiratory diseases, including COPD. An expanding body of evidence underscores that the composition of both the gastrointestinal and respiratory microbiome deviates in COPD patients compared to healthy individuals, leading to distinct host immune responses and clinical manifestations. The objective of this review is to provide a concise overview of the role of both gut and respiratory microbiome plays in the development of COPD. This will be accomplished by compiling current literature on the microbiome profile in stable and exacerbated cases of COPD, as well as exploring the biological mechanisms through a discussion of relevant experiments conducted on murine models. Hallmark characteristics of the microbial profile in COPD encompass reduced Prevotella spp. in the respiratory microbiome, culminating in a loss of anti-inflammatory protection, and diminished Bacteroidetes in the gut microbiome, leading to a decrease in protective short-chain fatty acids (SCFAs). The proliferation of Proteobacteria, particularly Haemophilus spp., Moraxella spp. and Pseudomonas spp. contributes to COPD pathologies via recognition of proinflammatory lipopolysaccharide (LPS) via Toll-like receptors (TLRs). As a consequence, deteriorated pulmonary function, enhanced severity, increased onset of exacerbations and elevated mortality were observed.

Genetic Insights into the Gut-Lung Axis: Mendelian Randomization Analysis on Gut Microbiota, Lung Function, and COPD

Background

Chronic obstructive pulmonary disease (COPD) is a respiratory disorder with a complex etiology involving genetic and environmental factors. The dysbiosis of gut microbiota has been implicated in COPD. Mendelian Randomization (MR) provides a tool to investigate causal links using genetic variants as instrumental variables. This study aims to employ MR analysis to explore the causal relationship between gut microbiota, lung function, and COPD.

Methods

We utilized genome-wide association study (GWAS) data from MiBioGen, UK Biobank and FinnGen, which were related to gut microbial taxa, lung function parameters including forced vital capacity in one second (FEV1), forced vital capacity (FVC), and percentage of predicted FEV1 (FEV1%pred), as well as GWAS data for COPD. MR analysis was conducted to assess the causal effects of gut microbiota on lung function and the risk of COPD. Sensitivity analysis was utilized to examine the stability of the causal relationships. Multiple testing and reverse analysis were employed to evaluate the robustness of these relationships.

Results

Using the IVW method, 64 causal correlations were identified. Through conducting sensitivity analysis, multiple testing, and reverse analysis, we identified 14 robust and stable causal relationships. The bacterial taxa that showed a positive association with lung function included Desulfovibrionaceae, Erysipelotrichales, Desulfovibrionales, Clostridiales, Clostridia, Deltaproteobacteria and Erysipelotrichia, while Selenomonadales and Negativicutes showed a negative association with lung function. The abundance of Holdemanella were positively correlated with the risk of COPD, while FamilyXIII exhibited a negative correlation with the risk of COPD.

Conclusion

Several microbial taxa were discovered to have a positive causal correlation with lung function, offering potential insights into the development of probiotics. The presence of microbial taxa negatively correlated with lung function and positively correlated with COPD emphasized the potential impact of gut microbiota dysbiosis on respiratory health.

Genetic evidence on the causality between gut microbiota and various asthma phenotypes: a two-sample Mendelian randomization study

Introduction

Asthma is a multifarious disease that manifests in various phenotypes. Among the various factors that contribute to the development of asthma, the gut microbiota has recently emerged as a compelling area of investigation. This study aims to investigate the causal relationships between gut microbiota and distinct asthma phenotypes.

Methods

The genome-wide association study (GWAS) summary statistics for 211 gut microbial taxa were used as study exposure. Five traits pertaining to various asthma phenotypes (asthma, allergic asthma, childhood asthma, suggestive for eosinophilic asthma and obesity-related asthma) were included as study outcome. We conducted Mendelian randomization (MR) analysis and sensitivity analysis for each bacterial taxa and asthma phenotypes.

Result

We discovered a total of 58 associations that exhibited evidence of causality. Out of these, 4 associations remained significant even after applying multiple correction. An increased risk of asthma was causally associated with higher abundance of genus Holdemanella (OR = 1.11; CI: 1.05-1.17; p = 0.027), genus Oxalobacter (OR = 1.09; CI: 1.04-1.15; p = 0.025) and genus Butyricimonas (OR = 1.14; CI: 1.06-1.22; p = 0.027). Order NB1n was causally linked with an increased risk of obesity-related asthma (OR = 1.17; CI: 1.07-1.29; p = 0.015). There was limited overlap among the taxa that exhibited potential causal relationships with distinct asthma phenotypes.

Conclusion

Our research has provided genetic evidence that establishes multiple causal relationships between the gut microbiota and distinct asthma phenotypes, supporting the role of the gut microbiota in various asthma phenotypes. It is possible that different taxa play a role in the development of distinct asthma phenotypes. The causal relationships identified in this study require further investigation.

Therapeutic potential of iron chelators in retinal vascular diseases

Iron is one of the necessary metal elements in the human body. There are numerous factors that control the balance of iron metabolism, and its storage and transportation mechanisms are intricate. As one of the most energy-intensive tissues in the body, the retina is susceptible to iron imbalance. The occurrence of iron overload in the retina leads to the generation of a significant quantity of reactive oxygen species. This will aggravate local oxidative stress and inflammatory reactions and even lead to ferroptosis, eventually resulting in retinal dysfunction. The blood-retina-retinal barrier is eventually harmed by oxidative stress and elevated inflammation, which are characteristics of retinal vascular disorders. The pathophysiology of retinal vascular disorders may be significantly influenced by iron. Recently, iron-chelating agents have been found to have antioxidative and anti-inflammatory actions in addition to iron chelating. Therefore, iron neutralization is considered to be a new and potentially useful therapeutic strategy. This article reviews the iron overload in retinal vascular diseases and discusses the therapeutic potential of iron-chelating agents.

Risk factors for diabetic foot ulcers: A systematic review and meta-analysis

OBJECTIVE

To systematically evaluate the risk factors for developing diabetic foot ulcers (DFU).

METHODS

The Cochrane Library, PubMed, Web of Science, SinoMed, CNKI, VIP, and Wanfang Data were searched for relevant studies on DFU risk factors, and the search time frame was from database creation to March 2022. Meta-analysis was performed using RevMan 5.3.

RESULTS

A total of 26 publications were included, including 3 cohort studies, 22 case-control studies, and one cross-sectional study. Meta-analysis showed that advanced age [MD = 6.04, 95% CI (3.92, 8.16)], male [OR = 1.84, 95% CI (1.48, 2.29)], elevated body mass index [MD = 1.58, 95% CI (0.47, 2.69)], prolonged duration of diabetes [MD = 2.72, 95% CI (2.33, 3.11)], comorbid nephropathy [OR = 3.15, 95% CI (2.68, 4.60)], comorbid neuropathy [OR = 4.80, 95% CI (2.79, 8.27)], comorbid retinopathy [OR = 3.37, 95% CI (2.26, 5.02)], elevated systolic blood pressure [OR = 8.19, 95% CI (6.33, 10.05)], elevated fasting glucose [MD = 1.60, 95% CI (0.21, 3.00)], elevated glycated hemoglobin [MD = 1.24, 95% CI (0.94, 1.54)], elevated triglycerides [MD = 0.44 (95% CI (0.15, 0.73)], elevated fibrinogen [MD = 1.35, 95% CI (0.62, 2.08)], elevated white blood cell count [MD = 2.56, 95% CI (2.24, 2.88)], elevated C-reactive protein [MD = 15.08, 95% CI (8.03, 22.13)], decreased ankle-brachial ratio [MD = -0.26, 95% CI (-0.36, -0.16)], and decreased total protein levels [MD = -4.58, 95% CI (-6.91, -2.25)] were risk factors for developing DFU (p < 0.05), and increased HDL cholesterol levels [MD = -0.22, 95% CI (-0.36, -0.08)] were protective factor for developing DFU (p < 0.05).

CONCLUSION

There are many risk factors for developing of ulcers in the diabetic feet, and early prevention and intervention should be performed as early as possible to assess the risk of developing diabetic foot patients.

Advances in medical treatment for pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (PanNENs) are rare neoplasms with strong heterogeneity that have experienced an increasing incidence rate in recent years. For patients with locally advanced or distant metastatic PanNENs, systemic treatment options vary due to the different differentiations, grades and stages. The available options for systemic therapy include somatostatin analogs, mole-cularly targeted agents, cytotoxic chemotherapeutic agents, immune checkpoint inhibitors, and peptide receptor radionuclide therapy. In addition, the development of novel molecularly targeted agents is currently in progress. The sequence of selection between different chemotherapy regimens has been of great interest, and resistance to chemotherapeutic agents is the major limitation in their clinical application. Novel agents and high-level clinical evidence continue to emerge in the field of antiangiogenic agents. Peptide receptor radionuclide therapy is increasingly employed for the treatment of advanced neuroendocrine tumors, and greater therapeutic efficacy may be achieved by emerging radio-labeled peptides. Since immune checkpoint inhibitor monotherapies for PanNENs appear to have limited antitumor activity, dual immune checkpoint inhibitor therapies or combinations of antiangiogenic therapies and immune checkpoint inhibitors have been applied in the clinic to improve clinical efficacy. Combining the use of a variety of agents with different mechanisms of action provides new possibilities for clinical treatments. In the future, the study of systemic therapies will continue to focus on the screening of the optimal benefit population and the selection of the best treatment sequence strategy with the aim of truly achieving individualized precise treatment of PanNENs.

[Current status and thoughts of non-surgical treatment of knee osteoarthritis]

Knee osteoarthritis (KOA) is a worldwide disease, and also the main cause of pain and disability in the motor system. Due to the aging population in China, extension of life expectancy and increased number of obese people, the number of people affected by KOA continues to surge. Neither surgical nor non-surgical treatment can change the disease process, but these interventions can reduce pain and disability. The treatment principle of KOA is to start with non-surgical treatment, which has been considered as the first choice for KOA patients due to its advantages of less complications, minimal invasiveness, and low medical cost. This article describes the non-surgical treatment of KOA, aiming to provide new insights into the clinical treatment of KOA.

Performance of radiomics models for tumour-infiltrating lymphocyte (TIL) prediction in breast cancer: the role of the dynamic contrast-enhanced (DCE) MRI phase

OBJECTIVE

To systematically investigate the effect of imaging features at different DCE-MRI phases to optimise a radiomics model based on DCE-MRI for the prediction of tumour-infiltrating lymphocyte (TIL) levels in breast cancer.

MATERIALS AND METHODS

This study retrospectively collected 133 patients with pathologically proven breast cancer, including 73 patients with low TIL levels and 60 patients with high TIL levels. The volumes of breast cancer lesions were manually delineated on T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and each phase of DCE-MRI, followed by 6250 quantitative feature extractions. The least absolute shrinkage and selection operator (LASSO) method was used to select predictive feature sets for the classifiers. Four models were developed for predicting TILs: (1) single enhanced phase radiomics models; (2) fusion enhanced multi-phase radiomics models; (3) fusion multi-sequence radiomics models; and (4) a combined radiomics-based clinical model.

RESULTS

Image features extracted from the delayed phase MRI, especially DCE_Phase 6 (DCE_P6), demonstrated dominant predictive performances over features from other phases. The fusion multi-sequence radiomics model and combined radiomics-based clinical model achieved the highest predictive performances with areas under the curve (AUCs) of 0.934 and 0.950, respectively; however, the differences were not statistically significant.

CONCLUSION

The DCE-MRI radiomics model, especially image features extracted from the delayed phases, can help improve the performance in predicting TILs. The radiomics nomogram is effective in predicting TILs in breast cancer.

KEY POINTS

• Radiomics features extracted from DCE-MRI, especially delayed phase images, help predict TIL levels in breast cancer. • We developed a nomogram based on MRI to predict TILs in breast cancer that achieved the highest AUC of 0.950.

Whole-Lesion Histogram Analysis of the Apparent Diffusion Coefficient as a Quantitative Imaging Biomarker for Assessing the Level of Tumor-Infiltrating Lymphocytes: Value in Molecular Subtypes of Breast Cancer

Purpose

To assess whether apparent diffusion coefficient (ADC) metrics can be used to assess tumor-infiltrating lymphocyte (TIL) levels in breast cancer, particularly in the molecular subtypes of breast cancer.

Methods

In total, 114 patients with breast cancer met the inclusion criteria (mean age: 52 years; range: 29–85 years) and underwent multi-parametric breast magnetic resonance imaging (MRI). The patients were imaged by diffusion-weighted (DW)-MRI (1.5 T) using a single-shot spin-echo echo-planar imaging sequence. Two readers independently drew a region of interest (ROI) on the ADC maps of the whole tumor. The mean ADC and histogram parameters (10^th, 25^th, 50^th, 75^th, and 90^th percentiles of ADC, skewness, entropy, and kurtosis) were used as features to analyze associations with the TIL levels in breast cancer. Additionally, the correlation between the ADC values and Ki-67 expression were analyzed. Continuous variables were compared with Student’s t-test or Mann-Whitney U test if the variables were not normally distributed. Categorical variables were compared using Pearson’s chi-square test or Fisher’s exact test. Associations between TIL levels and imaging features were evaluated by the Mann-Whitney U and Kruskal-Wallis tests.

Results

A statistically significant difference existed in the 10^th and 25^th percentile ADC values between the low and high TIL groups in breast cancer (P=0.012 and 0.027). For the luminal subtype of breast cancer, the 10^th percentile ADC value was significantly lower in the low TIL group (P=0.041); for the non-luminal subtype of breast cancer, the kurtosis was significantly lower in the low TIL group (P=0.023). The Ki-67 index showed statistical significance for evaluating the TIL levels in breast cancer (P=0.007). Additionally, the skewness was significantly higher for samples with high Ki-67 levels in breast cancer (P=0.029).

Conclusions

Our findings suggest that whole-lesion ADC histogram parameters can be used as surrogate biomarkers to evaluate TIL levels in molecular subtypes of breast cancer.

[Misdiagnosis analysis: 120 patients with nasal extranodal NK/T cell lymphoma in head and neck]

Objective:The Clinicopathological characteristics and the reason of misdiagnosis about nasal extranodal NK/T cell lymphoma in head and neck（ENKTL） are analysised to raise awareness and reduce misdiagnosis. Method:One hundred and twenty patients with ENKTL, diagnosed pathologically in head and neck from May 2010 to April 2018, were analyzed retrospectively. All cases were divided into misdiagnosed group and non-misdiagnosed group according to whether there were misdiagnosis and mistreatment before diagnosis. The differences of clinicopathological characteristics between the two groups before and after diagnosis were compared. The differences of overall survival（OS） between the two groups after treatment were also compared. Result:The misdiagnosis rate of this study was 71.7%, and they were misdiagnosed as sinusitis, nasal polyps, upper respiratory tract infection and so on. On the whole, the 1-year OS, 3-year OS and 5-year OS were 77.8%, 65.9% and 49.3% respectively. There was no significant difference in sex, age, first symptom, initial site, B symptom, superficial lymph node enlargement and weight loss between two groups before diagnosis（P>0.05）, however, there were significant differences in relative specific signs, hospital grade and time from first visit to definite diagnosis（P<0.05）. The proportion of the high-level hospitals in the first visit hospital was significantly lower than that in the non-misdiagnosed group, while the time from the first visit to the final diagnosis was significantly longer than that in the non-misdiagnosed group. There was no significant difference in international prognostic index（IPI） score, expression of Ki-67, therapeutic schedule, chemotherapy regimen for patients receiving chemotherapy, and radiation dose for patients receiving radiotherapy after diagnosis between the two groups（P>0.05）, but there was a significant difference in the clinical stages of Ann Arbor between the two groups（P<0.05）. The clinical staging of the misdiagnosed group was later than that of the non-misdiagnosed group. The 1-year OS, 3-year OS and 5-year OS were 73.6%, 59.3% and 43.2% in the misdiagnosed group respectively, and 88.2%, 82.4% and 64.2% in the non-misdiagnosed group respectively. The overall survival rate in the misdiagnosis group was lower than that in the non-misdiagnosed group, and the overall survival time was lower than that in the non-misdiagnosed group. However, there was no significant difference in the overall survival rates between the early stage（Ⅰ and Ⅱ） and the advanced stage（Ⅲ and Ⅳ） of Ann Arbor（P>0.05）. Conclusion:The non-specific clinical and the complexity of pathological features of ENKTL in head and neck might cause misdiagnosis, which leads to prolonged time from first visit to definite diagnosis, thus results in disease progression, and ultimately may lead to decreased overall survival rate. To avoid the misdiagnosis and early diagnosis is very important.

[Letrozole versus gonadotropin-releasing hormone antagonist during luteal phase in the prevention of ovarian hyperstimulation syndrome: a randomized controlled trial]

Objective: To explore and compare the preventive effect of using letrozole and gonadotropin-releasing hormone (GnRH) antagonist during luteal phase of patients at high risk for ovarian hyperstimulation syndrome (OHSS). Methods: A total of 99 infertile women undergoing in vitro fertilization and embryo transfer or intracytoplasmic sperm injection with high risk for OHSS were enrolled in this randomized controlled trial.The letrozole group (n=51) received letrozole of 7.5 mg daily for 3 days;the GnRH antagonist group (n=48) were given cetrorelix of 0.25 mg subcutaneously daily for 3 days. Both groups received support therapy combined with embryo cryopreservation. The incidence of OHSS was surveyed. And the serum concentration of estradiol, LH and progesterone on days 3, 5 and 8 after oocytes retrieval were measured. Results: There were no statistical differences in terms of baseline characteristics of patients and outcomes of controlled ovarian hyperstimulation between the two groups.The incidence of moderate and severe OHSS was found no significantly difference between letrozole group [11.8%(6/51)] and GnRH antagonist group [10.4%(5/48);P>0.05]. The estradiol concentration of the indicated days on days 3,5 and 8 after oocytes retrieval in letrozole group and GnRH antagonist group were (1 417±3 543) versus (15 210±9 921) pmol/L, (1 692±4 330) versus (18 680±11 567) pmol/L, (239±336) versus (3 582±5 427) pmol/L, respectively;compared with GnRH antagonist group, the estradiol level was significantly lower in the letrozole group (all P<0.01). The luteinizing hormone level in the letrozole group were (0.46±0.40), (0.56±0.55)and (0.67±0.58) U/L on days 3,5 and 8 after oocytes retrieval, which were significantly higher than those of GnRH antagonist group [(0.28±0.28), (0.30±0.19) and (0.45±0.37) U/L, respectively; all P<0.05]. There was no obvious differences on progesterone levels between letrozole group and GnRH antagonist group (all P>0.05),and on days 8 after oocytes retrieval,the level of progesterone in each group were significantly lower than those on day 3 and 5 after oocytes retrieval (P<0.05). Conclusion: Letrozole has the same efficiency as GnRH antagonist for the prevention of OHSS, faster and cheaper to use, but its efficacy seems not to be related to the suppression of steroidogenic during the luteal phase.

[Association of vitamin D receptor and its genetic polymorphisms with nasopharyngeal carcinoma]

Objective:To investigate the gene expression and polymorphisms of vitamin D receptor (VDR) in nasopharyngeal carcinoma. Method:The expression of VDR mRNA was detected by fluorescent quantitative PCR in PBMC from 48 patients with nasopharyngeal carcinoma and 48 controls. The FokI and ApaI loci of all subjects were detected by TaqMan-MGB fluorescent probe PCR. Result:The VDR mRNA △Ct value was 9.32±0.91 and 7.31±1.04 in nasopharyngeal carcinoma patients and controls, respectively. Using multivariate Logistic regression analysis, the results showed that the distribution of FokI point Ff genotype in the case group was significantly higher than that in the control group (adjusted OR=1.97, 95%CI=1.33-2.91). No difference was found between the control group and the patient group at ApaI loci. Further haplotype analysis was used to find that compared with fa haplotypes, the distribution of FokI Ff genotype in the case group was significantly higher than that in the healthy control group (adjusted OR=0.65, 95%CI=0.48-0.87). There were significant differences in the gene expression level of VDR among the patients with the different genotypes of FokI loci (F=194.5, P<0.01). Conclusion:Genetic variants of the VDR gene are closely associated with nasopharyngeal carcinoma.

Anti-site-induced diverse diluted magnetism in LiMgPdSb-type CoMnTiSi alloy

The effect of three kinds of anti-site disorder to electronic structure and magnetic properties of the LiMgPdSb-type CoMnTiSi alloy are investigated. It was found the Mn-Ti anti-site disorder can induce the diluted magnetism in CoMnTiSi matrix. The magnetic structure has an oscillation between the ferromagnetic and antiferromagnetic states with the different degree of Mn-Ti anti-site disorder. Two novel characteristics: the diluted antiferromagnetic half-metallicity and the diluted zero-gap half-metallity are found in the different degree range of the Mn-Ti anti-site disorder. The Co-Mn and Co-Ti anti-site disorder have little effect on the magnetic properties. The width of energy gap and the intensity of DOS at the Fermi level can be adjusted by the degree of Co-Mn or Co-Ti anti-site disorder. The independent control to the carrier concentration and magnetization can be realized by introducing the different anti-site disorder.

Driving magnetostructural transitions in layered intermetallic compounds

We report the dramatic effect of applied pressure and magnetic field on the layered intermetallic compound Pr(0.5)Y(0.5)Mn(2)Ge(2). In the absence of pressure or magnetic field this compound displays interplanar ferromagnetism at room temperature and undergoes an isostructural first order magnetic transition (FOMT) to an antiferromagnetic state below 158 K, followed by another FOMT at 50 K due to the reemergence of ferromagnetism as praseodymium orders (T(C)(Pr)). The application of a magnetic field drives these two transitions towards each other, whereas the application of pressure drives them apart. Pressure also produces a giant magnetocaloric effect such that a threefold increase of the entropy change associated with the lower FOMT (at T(C)(Pr)) is seen under a pressure of 7.5 kbar. First principles calculations, using density functional theory, show that this remarkable magnetic behavior derives from the strong magnetoelastic coupling of the manganese layers in this compound.

The magnetocaloric effect and critical behaviour of the Mn(0.94)Ti(0.06)CoGe alloy

Structural, magnetic and magnetocaloric properties of the Mn(0.94)Ti(0.06)CoGe alloy have been investigated using x-ray diffraction, DC magnetization and neutron diffraction measurements. Two phase transitions have been detected, at T(str) = 235 K and T(C) = 270 K. A giant magnetocaloric effect has been obtained at around T(str) associated with a structural phase transition from the low temperature orthorhombic TiNiSi-type structure to the high temperature hexagonal Ni(2)In-type structure, which is confirmed by neutron study. In the vicinity of the structural transition, at T(str), the magnetic entropy change, -ΔS(M) reached a maximum value of 14.8 J kg(-1) K(-1) under a magnetic field of 5 T, which is much higher than that previously reported for the parent compound MnCoGe. To investigate the nature of the magnetic phase transition around T(C) = 270 K from the ferromagnetic to the paramagnetic state, we performed a detailed critical exponent study. The critical components γ, β and δ determined using the Kouvel-Fisher method, the modified Arrott plot and the critical isotherm analysis agree well. The values deduced for the critical exponents are close to the theoretical prediction from the mean-field model, indicating that the magnetic interactions are long range. On the basis of these critical exponents, the magnetization, field and temperature data around T(C) collapse onto two curves obeying the single scaling equation M(H,ε) = ε(β)f ± (H/ε(β+γ)).

Iron doped hexagonal ErMnO3: structural, magnetic, and dielectric properties

The single phase ErFe(x)Mn1-xO3 (0 < or = x < or = 0.15) compounds were synthesized by the solid-state reaction method. The doping effects on the crystal structural, magnetic, thermal, and dielectric properties were systematically investigated. The XRD patterns show all samples crystallize in the hexagonal structure with P6(3)cm space group. The lattice parameters a and c first decrease with doping, which is followed by a subsequent increase at higher doping levels. Although both the Fe3+ and Mn3+ ions remain stable in high spin trivalent states in all samples, the magnetization is weakened with increasing Fe contents. The heat capacity data shows the antiferromagnetic transition slightly shifts from 77 K for ErMnO3 to 80 K for ErFe015Mn0.85O3, which can not be observed in the magnetic susceptibility data. The real part of complex impedance of these samples rises as the doping level increases, indicating the enhancement of insulativity of doped samples.

[Classification of the orbital margin fractures]

OBJECTIVE

To study the classification of the orbital margin fractures.

METHODS

There are 65 cases of the orbital margin fractures classified by Reduction-Orbital-Classification from January 1995 to December 1999 in Macau Conde de Sao Juanuario Hospital.

RESULTS

The 65 cases are classified into six type: I Stable orbital fracture, II Orbital floor (blow-out) fracture, III Orbital-zygomatic fracture, IV Orbital-naso-maxillary fracture, V Comminuted fracture of the inferior orbital rim, VI Complex orbital fractures.

CONCLUSION

The Reduction-Orbital-Classification are a complete, precise, practical, simple way for the orbital fractures; It not only presents the exist of the orbital margin fractures but also means the Classification for convenience of the treatment and treatment guiding the classification.