Synthesis and Characterization of Iron Bispyridine Bisdicyanamide, Fe[C5H5N]2[N(CN)2]2.

Fe[C5H5N]2[N(CN)2]2 (1) was synthesized from a reaction of stoichiometric amounts of NaN(CN)2 and FeCl2·4H2O in a methanol/pyridine solution. Single-crystal and powder diffraction show that 1 crystallizes in the monoclinic space group I2/m (no. 12), different from Mn[C5H5N]2[N(CN)2]2 (P21/c, no. 14) due to tilted pyridine rings, with a = 7.453(7) Å, b = 13.167(13) Å, c = 8.522(6) Å, ß = 114.98(6)° and Z = 2. ATR-IR, AAS, and CHN measurements confirm the presence of dicyanamide and pyridine. Thermogravimetric analysis shows that π-stacking interactions of the pyridine rings play an important role in structural stabilization. Based on DFT-optimized structures, a chemical bonding analysis was performed using a local-orbital framework by projection from a plane-wave basis. The resulting bond orders and atomic charges are in good agreement with the expectations based on the structure analysis. SQUID magnetic susceptibility measurements show a high-spin state FeII compound with predominantly antiferromagnetic exchange interactions at lower temperatures.

Evaluation of Scalable Synthesis Methods for Aluminum-Substituted Li7La3Zr2O12 Solid Electrolytes.

Solid electrolyte is the key component in all-solid-state batteries (ASBs). It is required in electrodes to enhance Li-conductivity and can be directly used as a separator. With its high Li-conductivity and chemical stability towards metallic lithium, lithium-stuffed garnet material Li7La3Zr2O12 (LLZO) is considered one of the most promising solid electrolyte materials for high-energy ceramic ASBs. However, in order to obtain high conductivities, rare-earth elements such as tantalum or niobium are used to stabilize the highly conductive cubic phase. This stabilization can also be obtained via high levels of aluminum, reducing the cost of LLZO but also reducing processability and the Li-conductivity. To find the sweet spot for a potential market introduction of garnet-based solid-state batteries, scalable and industrially usable syntheses of LLZO with high processability and good conductivity are indispensable. In this study, four different synthesis methods (solid-state reaction (SSR), solution-assisted solid-state reaction (SASSR), co-precipitation (CP), and spray-drying (SD)) were used and compared for the synthesis of aluminum-substituted LLZO (Al:LLZO, Li6.4Al0.2La3Zr2O12), focusing on electrochemical performance on the one hand and scalability and environmental footprint on the other hand. The synthesis was successful via all four methods, resulting in a Li-ion conductivity of 2.0-3.3 × 10-4 S/cm. By using wet-chemical synthesis methods, the calcination time could be reduced from two calcination steps for 20 h at 850 °C and 1000 °C to only 1 h at 1000 °C for the spray-drying method. We were able to scale the synthesis up to a kg-scale and show the potential of the different synthesis methods for mass production.

Infiltration Depth is the Most Relevant Risk Factor for Overall Metastases in Early Esophageal Adenocarcinoma.

BACKGROUND: Research in early esophageal adenocarcinoma focused on prediction of lymph node metastases in order to stratify patients for endoscopic treatment instead of esophagectomy. Although distant metastases were described in rates of up to 13% of patients within a follow-up of 3 years, their prediction has been neglected so far. METHODS: In a secondary analysis, a cohort of 217 patients (53 T1a and 164 T1b) treated by esophagectomy was analyzed for histopathological risk factors. Their ability to predict the combination of lymph node metastases at surgery as well as metachronous locoregional and distant metastases (overall metastatic rate) was assessed by uni- and multivariate logistic regression analysis. RESULTS: Tumor invasion depth was correlated with both lymph node metastases at surgery (τ = 0.141; P = .012), tumor recurrences (τ = 0.152; P = .014), and distant metastases (τ = 0.122; P = 0.04). Multivariate analysis showed an odds ratio of 1.31 (95% CI 1.02-1.67; P = .033) per increasing tumor invasion depth and of 3.5 (95% CI 1.70-6.56; P < .001) for lymphovascular invasion. The pre-planned subgroup analysis in T1b tumors demonstrated an even lower predictive ability of lymphovascular invasion with an odds ratio of 2.5 (95% CI 1.11-5.65; P = 0.028), whereas the predictive effect of sm2 (odds ratio 3.44; 95% CI 1.00-11.9; P = 0.049) and sm3 (odds ratio 3.44; 95% CI 1.00-11.9; P = 0.049) tumor invasion depth was similar. CONCLUSIONS: The present report demonstrates the insufficient risk prediction of histopathologic risk factors for the overall metastatic rate.

Syntheses and Characterization of Diammine-Nickel/Cobalt(II)-Bisdicyanamide M(NH3)2[N(CN)2]2 with M = Ni and Co.

Crystals of M(NH3)2[N(CN)2]2 with M = Ni and Co were obtained from the reaction of stoichiometric amounts of Na[N(CN)2] with NiCl2·6H2O or CoCl2·6H2O in aqueous, ammoniacal solutions. X-ray single-crystal structure analyses show that M(NH3)2[N(CN)2]2 with M = Ni and Co crystallize isotypically to each other and adopt the monoclinic space group P21/ c (no. 14). The lattice parameters of Ni(NH3)2[N(CN)2]2 are a = 5.8498(9) Å, b = 10.6739(12) Å, and c = 6.8089(17) Å, ß = 98.037(3)° and Z = 2, while those of Co(NH3)2[N(CN)2]2 are a = 5.8303(11) Å, b = 10.746(2) Å, c = 6.7773(13) Å, and ß = 96.422(3)°. In addition, the crystal structure of the nickel compound was refined from neutron powder diffraction, augmented by DFT calculations as regards atomic displacement parameters. The IR spectra of the title compounds exhibit modes typical for the dicyanamide anion and ammonia. The UV/vis spectrum of Ni(NH3)2[N(CN)2]2 shows that the dicyanamide moiety is a medium-field ligand. Additional superconducting quantum interference device (SQUID) magnetic susceptibility measurements of Ni(NH3)2[N(CN)2]2 and Co(NH3)2[N(CN)2]2 confirm not only significant high-spin moments of χm T = 1.24 cm3·K·mol-1 (µeff = 3.15 µB) and 2.89 cm3·K·mol-1 (µeff = 4.81 µB), respectively, at 290 K and 0.1 T but also an absence of magnetic ordering.

Carbodiimides as energy materials: which directions for a reasonable future?

A little less than a decade after their quantum-chemical prediction and eventual synthesis, solid-state transition-metal carbodiimides and closely related compounds have somewhat unexpectedly emerged as energy materials. In these carbodiimides, the O2- oxide dianion has been replaced by the complex NCN2- dianion, and the outstanding properties of such materials are likely related to their metastability and their higher amount of covalency compared to related oxides. When used as anode materials in rechargeable Li- and Na-ion batteries, one finds a conversion reaction, and further improving their performance will likely involve studying the redox behavior of NCN2-, the synthesis of novel ternary carbodiimides, in particular those with redox-active transition metals, and controlling their morphology. At present, such materials serve as catalysts in photochemical water oxidation, where they outperform their oxide cousins.

An MnNCN-Derived Electrocatalyst for CuWO4 Photoanodes.

CuWO4 is a photoanode candidate in neutral pH, and manganese-based oxygen evolution reaction electrocatalysts are of high interest due to their low price and low toxicity. Considering the unexplored chemistry of transition-metal carbodiimides/cyanamides for the PEC water oxidation, we investigated MnNCN as an electrocatalyst for CuWO4 under AM 1.5G illumination in potassium phosphate electrolyte (pH 7). Surface functionalization of CuWO4 photoanodes with MnNCN increased the photocurrent from 22 to 30 µA cm-2 at 1.23 V vs RHE. Complementary structural analysis by means of XRD and XPS revealed that MnNCN forms a core-shell structure MnNCN@MnPO x in phosphate electrolyte and mimics a manganese phosphate electrocatalyst. As such, the surface chemistry of MnNCN significantly differs from previous studies on the cobalt analogue (CoNCN). A separately prepared MnNCN electrode developed a small but detectable photocurrent due to photogenerated holes inside the semiconducting carbodiimide core of the MnNCN@MnPO x structure.

Lymph Node Retrieval is Inferior in the Modified Merendino Resection for Early Barrett's Carcinoma: A Matched-Pair Comparison with Ivor Lewis Resection.

AIM OF THE STUDY: A matched-pair comparison between the modified Merendino resection (MER) and Ivor Lewis resection (ILR) for early Barrett's carcinoma. BACKGROUND: Early adenocarcinoma of the esophagus (eACE) with positive risk factors for lymph node metastasis (LNM) needs surgery for cure. MER appeared to be an alternative to ILR. METHODS: Between July 2000 and July 2012, 156 patients with high-grade dysplasia or eACE received ILR, whereas in 30 cases MER was performed in a tertiary care center for GI Surgery. A matched-pair analysis was performed on the basis of sex, age, BMI, ASA classification and tumor stage. Thirty patients were assigned to each group. The data were analyzed regarding perioperative aspects (e.g., operating time, hospital stay, complications, number of lymph nodes) and survival analysis. RESULTS: The mean operating time was 301.7 min for ILR, compared to 255.4 min for MER (p = 0.044). The hospital stay following ILR was significantly longer than for MER (22.4 days ILR vs. 16.4 days MER, p = 0.023). There was no statistically significant difference regarding complications between the two groups (p = 0.463). The number of resected lymph nodes was significantly lower in the MER group (median 21) compared to the ILR group, where a median of 31 lymph nodes could be removed (p < 0.001). There was no statistically significant difference in overall (p = 0.145) or tumor-specific survival (p = 0.353). CONCLUSIONS: Lymph node retrieval is significantly inferior in the MER. Postoperative complication rates were comparable between the two operating techniques, although the operation time for ILR took longer and these patients required a longer hospital stay. MER should not be applied in cases with high risk of LNM.

Surgical Therapy of Early Carcinoma of the Esophagus.

BACKGROUND: The modern therapy of early esophageal carcinomas (pT1) requires an excellent cooperation between experienced gastroenterologists, pathologists, and esophageal surgeons. While endoscopic resection (ER) is accepted as the standard curative treatment for mucosal esophageal carcinomas, submucosal tumors are regarded as a strict indication for surgery. There is an ongoing discussion about the operative approach and the extent of lymph node dissection in these cases. METHODS: A literature review was performed to evaluate the operative treatment of early esophageal cancer. In view of oncological risk factors, treatment strategies, and operative procedures, current studies are summarized and compared to the results of our own center. RESULTS AND CONCLUSION: In early esophageal cancer, lymph node involvement is the only independent risk factor for survival and recurrence rates. There is evidence that infiltrated lymph nodes (N+) are significantly correlated with tumor infiltration depth, lymphovascular (L1) and microvascular invasion (V1), and poor tumor differentiation (G3). Several studies suggest that early squamous cell carcinomas (eSCCs) and early adenocarcinomas (eACs) have a different tumor biology and therefore need a different treatment strategy. While eSCCs in stage m1 and m2 can be cured by ER, tumors infiltrating the submucosal layer (sm1-3) show a high rate of lymph node metastasis (LNM); thus, surgical resection (SR) is clearly indicated. In tumors with invasion into the deep mucosa (m3) the risk of LNM is up to 11%; however, reliable data are rare and the type of therapy should be discussed with the patients individually. In eACs, ER is the standard curative treatment for all mucosal tumors (m1-m4) and sm1 tumors with low-risk constellation (G1, L0, VO, R0). All high-risk sm1 tumors and those with deeper submucosal infiltration (sm2, sm3) show a high rate of LNM and require SR. The standard operative procedure for early esophageal carcinomas is an Ivor-Lewis esophagectomy with radical, at least two-field lymphadenectomy.

Randomised prospective study for the effect of therapy on residual beta cell function in type-1 diabetes mellitus [ISRCTN70703138].

BACKGROUND: Newly diagnosed insulin-dependent diabetes mellitus is characterised by a temporary recovery of endogeneous insulin ("remission") after the beginning of medical treatment with subcutaneous insulin injections. Although most diabetologists think, that insulin reserve is related to reduced occurrence of diabetic long-term complications, such as eye, nerve and kidney disease, there is only one prospective controlled clinical study (the DCCT) addressing this question, however as secondary hypothesis. METHODS/DESIGN: Therefore, we composed a trial consisting of two cohorts with two therapeutic options within each cohort (conventional versus intensive therapy) and a three-year follow-up. In one group the patients are randomly assigned to the treatment regimes to test the statistical alternative hypothesis if variable insulin dosage is superior to fixed insulin injection in preserving insulin reserve measured by C-peptide in serum. Another group includes patients who prefer one of the two therapies, decline randomisation, but consent to follow-up. Apart from the determination of insulin reserve as a biological parameter a second primary endpoint was defined as 'therapeutic failure' according to the criteria of the European Association for the Study of Diabetes. Patients pass a training program to help them self-manage diabetes. A standardised protocol is being set up to minimize centre effects and bias of health care providers. Potential patient dependent bias will be investigated by questionnaires measuring psychic coping processes of people with diabetes. Management of visit dates is directly navigated by the database. Automated visit-reminders are mailed to patients and caregivers to optimise the number of visits on schedule. Data quality is regularly monitored and centres are informed on the results of continuous data management.