Reverse water-gas shift catalyzed by RhnVO3,4- (n = 3-7) cluster anions under variable temperatures.

A fundamental understanding of the exact structural characteristics and reaction mechanisms of interface active sites is vital to engineering an energetic metal-support boundary in heterogeneous catalysis. Herein, benefiting from a newly developed high-temperature ion trap reactor, the reverse water-gas shift (RWGS) (CO2 + H2 → CO + H2O) catalyzed by a series of compositionally and structurally well-defined RhnVO3,4- (n = 3-7) clusters were identified under variable temperatures (298-773 K). It is discovered that the Rh5-7VO3,4- clusters can function more effectively to drive RWGS at relatively low temperatures. The experimentally observed size-dependent catalytic behavior was rationalized by quantum-chemical calculations; the framework of RhnVO3,4- is constructed by depositing the Rhn clusters on the VO3,4 "support", and a sandwiched base-acid-base [Rhout--Rhin+-VO3,4-; Rhout and Rhin represent the outer and inner Rh atoms, respectively] feature in Rh5-7VO3,4- governs the adsorption and activation of reactants as well as the facile desorption of the products. In contrast, isolated Rh5-7- clusters without the electronic modification of the VO3,4 "support" can only catalyze RWGS under relatively high-temperature conditions.

Spectroscopic Characterization of Thermal Methane Activation by Lewis-Acid-Base Pair in a Gas-Phase Metal Nitride Anion Ta2N3.

Activation and transformation of methane is one of the "holy grails" in catalysis. Understanding the nature of active sites and mechanistic details via spectroscopic characterization of the reactive sites and key intermediates is of great challenge but crucial for the development of novel strategies for methane transformation. Herein, by employing photoelectron velocity-map imaging (PEVMI) spectroscopy in conjunction with quantum chemistry calculations, the Lewis acid-base pair (LABP) of [Taδ+-Nδ-] unit in Ta2N3 - acting as an active center to accomplish the heterolytic cleavage of C-H bond in CH4 has been confirmed by direct characterization of the reactant ion Ta2N3 - and the CH4-adduct intermediate Ta2N3CH4 -. Two active vibrational modes for the reactant (Ta2N3 -) and four active vibrational modes for the intermediate (Ta2N3CH4 -) were observed from the vibrationally resolved PEVMI spectra, which unequivocally determined the structure of Ta2N3 - and Ta2N3CH4 -. Upon heating, the LABP intermediate (Ta2N3CH4 -) containing the NH and Ta-CH3 unit can undergo the processes of C-N coupling and dehydrogenation to form the product with an adsorbed HCN molecule.

Volatile and semi-volatile organic compounds in landfill gas: Composition characteristics and health risks.

Gas emitted from landfills contains a large quantity of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), some of which are carcinogenic, teratogenic, and mutagenic, thereby posing a serious threat to the health of landfill workers and nearby residents. However, the global hazards of VOCs and SVOCs in landfill gas to human health remain unclear. To quantify the global risk distributions of these pollutants, we collected the composition and concentration data of VOCs and SVOCs from 72 landfills in 20 countries from the core database of Web of Science and assessed their human health risks as well as analyzed their influencing factors. Organic compounds in landfill gas were found to primarily result from the biodegradation of natural organic waste or the emissions and volatilization of chemical products, with the concentration range of 1 × 10-1-1 × 106 µg/m3. The respiratory system, in particular, lung was the major target organ of VOCs and SVOCs, with additional adverse health impacts ranging from headache and allergies to lung cancer. Aromatic and halogenated compounds were the primary sources of health risk, while ethyl acetate and acetone from the biodegradation of natural organic waste also exceeded the acceptable levels for human health. Overall, VOCs and SVOCs affected residents within 1,000 m of landfills. Air temperature, relative humidity, air pressure, wind direction, and wind speed were the major factors that influenced the health risks of VOCs and SVOCs. Currently, landfill risk assessments of VOCs and SVOCs are primarily based on respiratory inhalation, with health risks due to other exposure routes remaining poorly elucidated. In addition, potential health risks due to the transport and transformation of landfill gas emitted into the atmosphere should be further studied.

Sub-differentiation of PI-RADS 3 lesions in TZ by advanced diffusion-weighted imaging to aid the biopsy decision process.

Background: Performing biopsy for intermediate lesions with PI-RADS 3 has always been controversial. Moreover, it is difficult to differentiate prostate cancer (PCa) and benign prostatic hyperplasia (BPH) nodules in PI-RADS 3 lesions by conventional scans, especially for transition zone (TZ) lesions. The purpose of this study is sub-differentiation of transition zone (TZ) PI-RADS 3 lesions using intravoxel incoherent motion (IVIM), stretched exponential model, and diffusion kurtosis imaging (DKI) to aid the biopsy decision process. Methods: A total of 198 TZ PI-RADS 3 lesions were included. 149 lesions were BPH, while 49 lesions were PCa, including 37 non-clinical significant PCa (non-csPCa) lesions and 12 clinical significant PCa (csPCa) lesions. Binary logistic regression analysis was used to examine which parameters could predict PCa in TZ PI-RADS 3 lesions. The ROC curve was used to test diagnostic efficiency in distinguishing PCa from TZ PI-RADS 3 lesions, while one-way ANOVA analysis was used to examine which parameters were statistically significant among BPH, non-csPCa and csPCa. Results: The logistic model was statistically significant (χ2 = 181.410, p<0.001) and could correctly classify 89.39% of the subjects. Parameters of fractional anisotropy (FA) (p=0.004), mean diffusion (MD) (p=0.005), mean kurtosis (MK) (p=0.015), diffusion coefficient (D) (p=0.001), and distribute diffusion coefficient (DDC) (p=0.038) were statistically significant in the model. ROC analysis showed that AUC was 0.9197 (CI 95%: 0.8736-0.9659). Sensitivity, specificity, positive predictive value and negative predictive value were 92.1%, 80.4%, 93.9% and 75.5%, respectively. FA and MK of csPCa were higher than those of non-csPCa (all p<0.05), while MD, ADC, D, and DDC of csPCa were lower than those of non-csPCa (all p<0.05). Conclusion: FA, MD, MK, D, and DDC can predict PCa in TZ PI-RADS 3 lesions and inform the decision-making process of whether or not to perform a biopsy. Moreover, FA, MD, MK, D, DDC, and ADC may have ability to identify csPCa and non-csPCa in TZ PI-RADS 3 lesions.

C-H Activation by Iron-Vanadium Bimetallic Oxide Cluster Anions FeV3 O10 - and FeV5 O15 - : A Comparison with Scandium-Vanadium Oxide Clusters.

Late transition metal-bonded atomic oxygen radicals (LTM-O⋅- ) have been frequently proposed as important active sites to selectively activate and transform inert alkane molecules. However, it is extremely challenging to characterize the LTM-O⋅- -mediated elementary reactions for clarifying the underlying mechanisms limited by the low activity of LTM-O⋅- radicals that is inaccessible by the traditional experimental methods. Herein, benefiting from our newly-designed ship-lock type reactor, the reactivity of iron-vanadium bimetallic oxide cluster anions FeV3 O10 - and FeV5 O15 - featuring with Fe-O⋅- radicals to abstract a hydrogen atom from C2 -C4 alkanes has been experimentally characterized at 298 K, and the rate constants are determined in the orders of magnitude of 10-14 to 10-16  cm3 molecule-1 s-1 , which are four orders of magnitude slower than the values of counterpart ScV3 O10 - and ScV5 O15 - clusters bearing Sc-O⋅- radicals. Theoretical results reveal that the rearrangements of the electronic and geometric structures during the reaction process function to modulate the activity of Fe-O⋅- . This study not only quantitatively characterizes the elementary reactions of LTM-O⋅- radicals with alkanes, but also provides new insights into structure-activity relationship of M-O⋅- radicals.

Reverse water-gas shift reaction catalyzed by diatomic rhodium anions.

The reverse water-gas shift (RWGS, CO2 + H2 → CO + H2O, ΔH298 = +0.44 eV) reaction mediated by the diatomic anion Rh2- was successfully constructed. The generation of a gas-phase H2O molecule and ion product [Rh2(CO)ads]- was identified unambiguously at room temperature and the only elementary step that requires extra energy to complete the catalysis is the desorption of CO from [Rh2(CO)ads]-. This experimentally identified Rh2- anion represents the first gas-phase species that can drive the RWGS reaction because it is challenging to design effective routes to yield H2O from CO2 and H2. The reactions were performed by using our newly developed double ion trap reactors and characterized by mass spectrometry, photoelectron spectroscopy, and high-level quantum-chemical calculations. We found that the order that the reactants (CO2 or D2) were fed into the reactor did not have a pronounced impact on the reactivity and the final product distribution (D2O and Rh2CO-). The atomically precise insights into the key steps to guide the reaction toward the RWGS direction were provided.

Peptide-Based Sensing, Logic Computing, and Information Security on the Antimonene Platform.

Peptides have higher information density than DNA and equivalent molecular recognition ability and durability. However, there are currently no reports on the comprehensive use of peptides' recognition ability and structural diversity for sensing, logic computing, information coding, and protection. Herein, we, for the first time, demonstrate peptide-based sensing, logic computing, and information security on the antimonene platform. The molecular recognition capability and structural diversity (amino acid sequence) of peptides (Pb2+-binding peptide DHHTQQHD as a model) adsorbed on the antimonene universal fluorescence quenching platform were comprehensively utilized to sense targets (Pb2+) and give a response (fluorescence turn-on) and then to encode, encrypt, and hide information. Fluorescently labeled peptides used as the recognition probe and the information carrier were quenched and hidden by the large-plane two-dimensional material antimonene and specifically bound by Pb2+ as the stego key, resulting in fluorescence recovery. The above interaction and signal change can be considered as a peptide-based sensing and steganographic process to further implement quantitative detection of Pb2+, complex logic operation, information coding, encrypting, and hiding using a peptide sequence and the binary conversion of its selectivity. This research provides a basic paradigm for the construction of a molecular sensing and informatization platform and will inspire the development of biopolymer-based molecular information technology (processing, communication, control, security).

Water Gas Shift Reaction Catalyzed by Rhodium-Manganese Oxide Cluster Anions.

Fundamental understanding of the nature of active sites in real-life water gas shift (WGS) catalysts that can convert CO and H2O into CO2 and H2 is crucial to engineer related catalysts performing under ambient conditions. Herein, we identified that the WGS reaction can be, in principle, catalyzed by rhodium-manganese oxide clusters Rh2MnO1,2- in the gas phase at room temperature. This is the first example of the construction of such a potential catalysis in cluster science because it is challenging to discover clusters that can abstract the oxygen from H2O and then supply the anchored oxygen to oxidize CO. The WGS reaction was characterized by mass spectrometry, photoelectron spectroscopy, and quantum-chemical calculations. The coordinated oxygen in Rh2MnO1,2- is paramount for the generation of an electron-rich Mn+-Rh- bond that is critical to capture and reduce H2O and giving rise to a polarized Rh+-Rh- bond that functions as the real redox center to drive the WGS reaction.

Diagnostic Performance of PI-RADS v2, Proposed Adjusted PI-RADS v2 and Biparametric Magnetic Resonance Imaging for Prostate Cancer Detection: A Preliminary Study.

PURPOSE: To evaluate the diagnostic performance of PI-RADS v2, proposed adjustments to PI-RADS v2 (PA PI-RADS v2) and biparametric magnetic resonance imaging (MRI) for prostate cancer detection. METHODS: A retrospective cohort of 224 patients with suspected prostate cancer was included from January 2016 to November 2018. All the patients underwent a multi-parametric MR scan before biopsy. Two radiologists independently evaluated the MR examinations using PI-RADS v2, PA PI-RADS v2, and a biparametric MRI protocol, respectively. Receiver operating characteristic (ROC) curves for the three different protocols were drawn. RESULTS: In total, 90 out of 224 cases (40.18%) were pathologically diagnosed as prostate cancer. The area under the ROC curves (AUC) for diagnosing prostate cancers by biparametric MRI, PI-RADS v2, and PA PI-RADS v2 were 0.938, 0.935, and 0.934, respectively. For cancers in the peripheral zone (PZ), the diagnostic sensitivity was 97.1% for PI-RADS v2/PA PI-RADS v2 and 96.2% for biparametric MRI. Moreover, the specificity was 84.0% for biparametric MRI and 58.0% for PI-RADS v2/PA PI-RADS v2. For cancers in the transition zone (TZ), the diagnostic sensitivity was 93.4% for PA PI-RADS v2 and 88.2% for biparametric MRI/PI-RADS v2. Furthermore, the specificity was 95.4% for biparametric MRI/PI-RADS v2 and 78.0% for PA PI-RADS v2. CONCLUSIONS: The overall diagnostic performance of the three protocols showed minimal differences. For lesions assessed as being category 3 using the biparametric MRI protocol, PI-RADS v2, or PA PI-RADS v2, it was thought prostate cancer detection could be improved. Attention should be paid to false positive results when PI-RADS v2 or PA PI-RADS v2 are used.

Oxidation of isoprene by titanium oxide cluster cations in the gas phase.

The heterogeneous oxidation of isoprene (C5H8) by metal-oxide particles, such as the typical mineral aerosols TiO2, plays an important role in the isoprene atmospheric chemistry. However, the underlying mechanism of C5H8 oxidation remains elusive owing to the complexities of aerosol surfaces and reaction channels. Herein, we report the gas-phase reactions of TixOy+ (x = 1-7, y = 1-14) cations with isoprene by using mass spectrometry and density functional theory (DFT) calculations. Five types of reaction channels were observed: association, hydrogen atom transfer (HAT), C-C bond cleavage, combined oxygen atom transfer (OAT) and HAT and combined OAT and C-C bond cleavage. It is noteworthy that formaldehyde is known as the major oxidation product of isoprene/hydroxyl radicals in the atmosphere. In addition, CO has not been observed in the reactions of isoprene with gas-phase ions. Therefore, the reaction mechanisms of CH2O and CO generation observed in Ti2O5+/C5H8 and Ti4O8+/C5H8 systems were further investigated by DFT calculations, and the calculated results are in agreement with the experimental observations. In these two reactions, both Ti and O atoms can be the adsorption sites for C5H8. The reaction channels and mechanistic information gained in these gas-phase model reactions may offer fundamental insights relevant to the corresponding oxidation processes over titanium oxide aerosols in the atmosphere.

Ophthalmological outcomes of unilateral coronal synostosis in young children.

BACKGROUND: To report refractive outcomes, describe types of strabismus and evaluate the outcomes of surgical intervention for unilateral coronal synostosis (UCS) in paediatric patients. METHODS: This study retrospectively included 30 UCS cases. Patients aged from 3 months to 6 years (median: 1.8 years) were enrolled from January 2018 to December 2019 at Shanghai Children's Hospital. Sixteen patients had all types of strabismus; 15 of these patients underwent surgery. RESULTS: Refractive errors of 30 cases were included. In 60% of patients, astigmatism of 1.00D or more existed in not less than one eye at last record. Twenty (66.7%) patients had the larger amount of astigmatism in the contralateral eye. Fifteen patients received strabismus surgery, of whom 6 patients with monocular elevation deficiency (MED) underwent the standard Knapp procedure, with or without a horizontal deviation procedure. Fifteen cases were horizontally aligned within 5 prism dioptres (Δ). Six patients with MED (100%) had attained ≥25% elevation improvement after surgery, and the vertical deviation decreased from 25.83 Δ ± 4.92 Δ (range, 20 Δ-30 Δ) to 0.83 Δ ± 4.92 Δ after surgery (range, 0 Δ-10 Δ), for an improvement of 26.67 Δ ± 4.08 Δ (t = 16 P < 0.05). In 1 patient with esotropia, the horizontal deviation decreased from + 80 Δ to + 5 Δ after surgery. One patient was diagnosed with trichiasis and one with contralateral lacrimal duct obstruction. CONCLUSIONS: Contralateral MED was also the main type of strabismus in UCS. Superior oblique muscle palsy was still the most common, as previously reported. There is a risk of developing a higher astigmatism and anisometropia in the contralateral eye to synostosis. Other ophthalmic disorders should be treated in a timely manner. TRIAL REGISTRATION: The study was approved by the Institutional Review Board of Shanghai Children's Hospital (approval No. 2020R023-E01) and adhered to the tenets of the Declaration of Helsinki. Ethics approval was procured on March 30, 2020. This was a retrospective study. Written informed consent was sought from the patients' parents or legal guardians. Clinical Trials Registry number: ChiCTR2000034910 . Registration URL: http://www.chictr.org.cn/showproj.aspx?proj=56726 .

Sensitive Detection of Gas-Phase Glyoxal by Electron Attachment Reaction Ionization Mass Spectrometry.

Glyoxal (GLY) acts as a key contributor to tropospheric ozone production and secondary organic aerosol (SOA) formation on local to regional scales. The detection of GLY provides useful indicators of fast photochemistry occurring in the lower troposphere. The fast and sensitive detection of GLY is thus important, while traditional chemical ionization such as the proton-transfer reaction (PTR) is extremely limited by the poor detection limit and extensive fragmentation. To address these limitations, electron attachment reaction (EAR) ionization was applied to detect GLY. The generation of parent anions (GLY-) without fragmentation was observed, and cryogenic photoelectron imaging spectroscopy further characterized the structure of GLY-. The detection limit was estimated to be as low as (52 ± 1) pptv (parts per trillion by volume) with 1 min measurements. Other components in ambient air, such as water, carbon dioxide, and trace gases (acetone, propanal, etc.) have no effect on the detection of GLY. The EAR ionization is more promising than PTR ionization in detecting GLY. The detection of GLY in ambient air by the EAR ionization has been demonstrated.

Dual energy computed tomography for detection of metastatic lymph nodes in patients with hepatocellular carcinoma.

BACKGROUND: Regional lymph node metastasis in patients with hepatocellular carcinoma (HCC) is not uncommon, and is often under- or misdiagnosed. Regional lymph node metastasis is associated with a negative prognosis in patients with HCC, and surgical resection of lymph node metastasis is considered feasible and efficacious in improving the survival and prognosis. It is critical to characterize lymph node preoperatively. There is currently no consensus regarding the optimal method for the assessment of regional lymph nodes in patients with HCC. AIM: To evaluate the diagnostic value of single source dual energy computed tomography (CT) in regional lymph node assessment for HCC patients. METHODS: Forty-three patients with pathologically confirmed HCC who underwent partial hepatectomy with lymphadenectomy were retrospectively enrolled. All patients underwent dual-energy CT preoperatively. Regional lymph nodes (n = 156) were divided into either a metastatic (group P, n = 52) or a non-metastasis group (group N, n = 104), and further, according to pathology, divided into an active hepatitis (group P1, n = 34; group N1, n = 73) and a non-active hepatitis group (group P2, n = 18; group N2, n = 31). The maximal short axis diameter (MSAD), iodine concentration (IC), normalized IC (NIC), and the slope of the spectral curve (λ HU) of each group in the arterial phase (AP), portal phase (PP), and delayed phase (DP) were analyzed. RESULTS: Analysis of the MSAD, IC, NIC, and λ HU showed statistical differences between groups P and N (P < 0.05) during all three phases. To distinguish benign from metastatic lymph nodes, the diagnostic efficacy of IC, NIC, and λ HU in the PP was the best among the three phases (AP, PP, and DP), with a sensitivity up to 81.9%, 83.9%, and 81.8%, and a specificity up to 82.4%, 84.1% and 84.1%, respectively. The diagnostic value of combined analyses of MSAD with IC, NIC, or λ HU in the PP was superior to the dual energy CT parameters alone, with a sensitivity up to 84.5%, 86.9%, and 86.2%, and a specificity up to 83.0%, 93.6% and 89.8%, respectively. Between groups P1 and P2 and groups N1 and N2, only IC, NIC, and λ HU between groups N1 and N2 in the PP had a statistically significant difference (P < 0.05). CONCLUSION: Dual-energy CT contributes beneficially to regional lymph node assessment in HCC patients. Combination of MSAD with IC, NIC, or λ HU values in the PP is superior to using any single parameter alone. Active hepatitis does not deteriorate the capabilities for characterization of metastatic lymph nodes.

Interleukin-35 suppresses antitumor activity of circulating CD8+ T cells in osteosarcoma patients.

Purpose/Aim of the study: Interleukin (IL)-35 is a newly identified IL-12 cytokine family member and reveals immunosuppressive activity to CD8+ T cells in inflammation, infectious diseases, and cancers. However, little is known regarding IL-35 function in osteosarcoma. Thus, the aim of the current study was to investigate the regulatory function of IL-35 to CD8+ T cells in osteosarcoma. Materials and methods: Thirty-five osteosarcoma patients and 20 healthy individuals were enrolled. Serum CD4+CD25+CD127dim/- regulatory T cells (Tregs) and CD8+ T cells were purified. IL-35 concentration in serum and cultured supernatants was measured by enzyme-linked immunosorbent assay. Osteosarcoma cell line MG-63 cells and CD8+ T cells were stimulated with recombinant IL-35 in vitro, and modulatory function of IL-35 on these cells was assessed by investigation of cellular proliferation, cell cycle, apoptosis, and cytokine production. Results: Serum IL-35 and Treg-secreting IL-35 were significantly elevated in osteosarcoma patients. IL-35 stimulation did not affect proliferation, apoptosis, or cell cycle of MG-63 cells. Purified peripheral CD8+ T cells from osteosarcoma patients revealed dysfunctional property, which presented as decreased mRNA expressions for perforin, granzyme B, and granulysin, as well as reduced cytolytic (direct lysis of target MG-63 cells) and noncytolytic (interferon-γ and tumor necrosis factor-α production) function in coculture systems. Moreover, IL-35 stimulation further diminished cytolytic and noncytolytic activity of CD8+ T cells from osteosarcoma patients. Conclusions: The current data indicated that IL-35 contributed to CD8+ T-cell dysfunction and limited antitumor immune response in osteosarcoma.

Electron Attachment Reaction Ionization of Gas-Phase Methylglyoxal.

Methylglyoxal (MGLY) plays a significant role in atmospheric chemistry by serving as a key contributor to the formation of active free radicals, ozone, and secondary organic aerosol. Detection of MGLY by traditional chemical ionization such as proton-transfer reaction has several shortcomings such as parent molecule fragmentation. In this study, an electron attachment reaction (EAR) ionization method has been developed for the effective detection of MGLY. Almost no fragmentation was observed during the EAR. The generation of MGLY- anion in the EAR was further confirmed by cryogenic photoelectron imaging spectroscopy. The concentration of MGLY can be calibrated by using dibromomethane (CH2Br2) as reference gas. The detection sensitivity of MGLY was estimated to be (100 ± 2) mV/ppbv (parts per billion by volume). The O2, H2O, CO2, and trace gases in ambient air have no obvious effects on the detection of MGLY- anion by the EAR ionization method.

Formation of Acetylene in the Reaction of Methane with Iron Carbide Cluster Anions FeC3- under High-Temperature Conditions.

The underlying mechanism for non-oxidative methane aromatization remains controversial owing to the lack of experimental evidence for the formation of the first C-C bond. For the first time, the elementary reaction of methane with atomic clusters (FeC3- ) under high-temperature conditions to produce C-C coupling products has been characterized by mass spectrometry. With the elevation of temperature from 300 K to 610 K, the production of acetylene, the important intermediate proposed in a monofunctional mechanism of methane aromatization, was significantly enhanced, which can be well-rationalized by quantum chemistry calculations. This study narrows the gap between gas-phase and condensed-phase studies on methane conversion and suggests that the monofunctional mechanism probably operates in non-oxidative methane aromatization.

Size-Dependent Reactivity of Nano-Sized Neutral Manganese Oxide Clusters toward Ethylene.

Neutral manganese oxide clusters with the general composition Mn2 N O3 N+x (N=2-22; x=-1, 0, 1) with dimensions up to a nanosize were prepared by laser ablation and reacted with C2 H4 in a fast flow reactor. The size-dependent reactivity of C2 H4 adsorption on these clusters was experimentally identified and the adsorption reactivity decreases generally with an increase of the cluster size. Density functional theory calculations were performed to study the geometrical and electronic structures of the Mn2 N O3 N (N=1-6) clusters. The calculated results indicated that the coordination number and the charge distribution of the metal centers are responsible for the experimentally observed size-dependent reactivity. The highly charged Mn atoms with low coordination are preferential to adsorb C2 H4 . In contrast, the neutral manganese oxide clusters are completely inert toward the saturated hydrocarbon molecule C2 H6 . This work provides new perspectives to design related materials in the separation of hydrocarbon molecules.

Middle ear adenoma with uncommon presentation and literature review.

Middle ear adenoma (MEA) is a rare benign tumour. Here we report a case of MEA in a 39-year-old man with hearing loss. Some significant histopathological features of MEA and neuroendocrine differentiation identified by immunohistochemistry are described. The tumour showed remarkable and rare degenerative histological characteristics. There were a few tumour cells which were covered by degenerated tissue. Consequently, following frozen biopsy, the tumour was misdiagnosed as chronic ear inflammation. No recurrence was seen in this patient after 45 months of follow-up; regular clinical and radiological follow-up is necessary since recurrence is possible. A literature review for MEA is presented and this type of tumour is discussed clinically, microscopically and immunohistochemically. The differential diagnosis and associated treatment are described.

Dry eye and corneal sensitivity after small incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis: a Meta-analysis.

AIM: To assess the corneal sensitivity and the incidences of dry eye after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). METHODS: The Meta-analysis was performed using RevMan 5.3. We searched on PubMed from inception to March 2016. Summary weighted mean difference (WMD) and 95% confidence intervals (CIs) were used to analyze the datum. Random-effects or fixed-effects models were chosen up to between-study heterogeneity. The main outcomes were composed of the Ocular Surface Disease Index (OSDI) scores, tear film break-up time (TBUT), Schirmer Test and corneal sensitivity. RESULTS: Eight eligible studies including 772 eyes (386 in SMILE group and 386 in FS-LASIK group) were identified. The parameters have no significiant difference heterogeneity between SMILE and FS-LASIK group preoperatively. There were significant differences between the two groups in OSDI scores at one and three months postoperatively, in TBUT at one and three months postoperatively, in corneal sensitivity at one week, about one month and three months postoperatively. However, there was no significant difference observed in Schirmer Test at the follow-up periods. CONCLUSION: Compare to FS-LASIK, dry eye and the corneal sensitivity recover better in the SMILE group, in first three months after the surgery.

Giant Serous Cystadenoma of the Pancreas (⩾10 cm): The Clinical Features and CT Findings.

Purpose. To report the clinical features and CT manifestations of giant pancreatic serous cystadenoma (≥10 cm). Methods. We retrospectively reviewed the clinical features and CT findings of 6 cases of this entity. Results. All 6 patients were symptomatic. The tumors were 10.2 cm-16.5 cm (median value, 13.0 cm). CT imaging revealed that all 6 cases showed microcystic appearances (n = 5) or mixed microcystic and macrocystic appearances (n = 1). Five patients with tumors at the distal end of the pancreas received distal pancreatectomy. Among these 5 patients, 2 patients underwent partial transverse colon resection or omentum resection due to close adhesion. One patient whose tumor was located in the pancreatic head underwent pancreaticoduodenectomy; however, due to encasement of the portal and superior mesenteric veins, the tumor was incompletely resected. One patient had abundant draining veins on the tumor surface and suffered large blood loss (700 mL). After 6-49 months of follow-up the 6 patients showed no tumor recurrence or signs of malignant transformation. Conclusions. Giant pancreatic serous cystadenoma necessitates surgical resection due to large size, symptoms, uncertain diagnosis, and adjacent organ compression. The relationship between the tumors and the neighboring organs needs to be carefully assessed before operation on CT image.