The Fe-MAN Challenge: Ferrates-Microkinetic Assessment of Numerical Quantum Chemistry.

Organometallic species, such as organoferrate ions, are prototypical nucleophiles prone to reacting with a wide range of electrophiles, including proton donors. In solution, the operation of dynamic equilibria and the simultaneous presence of several organometallic species severely complicate the analysis of these fundamentally important reactions. This can be overcome by gas-phase experiments on mass-selected ions, which allow for the determination of the microscopic reactivity of the target species.

Mammographic density in relation to breast cancer recurrence and survival in women receiving neoadjuvant chemotherapy.

Objective: The association between mammographic density (MD) and breast cancer (BC) recurrence and survival remains unclear. Patients receiving neoadjuvant chemotherapy (NACT) are in a vulnerable situation with the tumor within the breast during treatment. This study evaluated the association between MD and recurrence/survival in BC patients treated with NACT.

Obesity and breast cancer prognosis: pre-diagnostic anthropometric measures in relation to patient, tumor, and treatment characteristics.

Purpose: Examine the association between obesity and clinical outcomes in early breast cancer and assess if patient, tumor, and treatment characteristics modify such associations in Malmö Diet and Cancer Study patients (MDCS).

Methods: The MDCS enrolled 17,035 Swedish women from 1991 to 1996. At enrollment, participants' body mass index (BMI), waist circumference and body fat percentage measures were collected.

On the accuracy of orbital based multi-level approaches for closed-shell transition metal chemistry.

In this work, we investigate the accuracy of the local molecular orbital molecular orbital (LMOMO) scheme and projection-based wave function-in-density functional theory (WF-in-DFT) embedding for the prediction of reaction energies and barriers of typical reactions involving transition metals. To analyze the dependence of the accuracy on the system partitioning, we apply a manual orbital selection for LMOMO as well as the so-called direct orbital selection (DOS) for both approaches. We benchmark these methods on 30 closed shell reactions involving 16 different transition metals.

On the Reactivity of Phosphaalumenes towards C-C Multiple Bonds.

Heterocycles containing group 13 and 15 elements such as borazines are an integral part of organic, biomedical and materials chemistry. Surprisingly, heterocycles containing P and Al are rare. We have now utilized phosphaalumenes in reactions with alkynes, alkenes and conjugated double bond systems.

Postoperative Hypocalcemia following Non-Cardiac Surgical Procedures in Children with 22q11.2 Deletion Syndrome.

The guidelines for management of children with 22q11.2 deletion syndrome (22q11DS) highlight the risk for developing hypocalcemia after surgery and recommend monitoring calcium perioperatively. Despite this guidance, little has been published on postoperative hypocalcemia and 22q11DS.

Statin use and patterns of breast cancer recurrence in the Malmö Diet and Cancer Study.

Background: Accumulating evidence suggests that statins have a beneficial effect on breast cancer prognosis. Previous studies have reported a positive association between statin use and breast cancer survival; however, the relationship between statin use and patterns of breast cancer recurrence remains unclear.

Patients And Methods: We identified all Malmö Diet and Cancer Study (MDCS) participants diagnosed with incident invasive breast cancer between 2005 and 2014.

22q11.2 duplications: Expanding the clinical presentation.

22q11.2 duplication syndrome has a frequency of ~1/700 in the intellectual disability population. Despite this frequency, there is limited information on the variable clinical presentation.

Circulating lipids and breast cancer prognosis in the Malmö diet and cancer study.

Purpose: Examine the association between circulating lipids and breast cancer outcomes in patients enrolled in the Malmö Diet and Cancer Study (MDCS).

Patients And Methods: Circulating lipid levels were measured in blood sampled upon enrollment in the female MDCS cohort (N = 17,035). We identified all MDCS participants with incident invasive breast cancer diagnosed between 1991 and 2014.

Reactivity of the Bicyclic Amido-Substituted Silicon(I) Ring Compound Si {N(SiMe )Mes} with FLP-Type Character.

The bicyclic amido-substituted silicon(I) ring compound Si {N(SiMe )Mes} 2 (Mes=Mesityl=2,4,6-Me C H ) features enhanced zwitterionic character and different reactivity from the analogous compound Si {N(SiMe )Dipp} 1 (Dipp=2,6- Pr C H ) due to the smaller mesityl substituents. In a reaction with the N-heterocyclic carbene NHC (1,3,4,5-tetramethyl-imidazol-2-ylidene), we observe adduct formation to give Si {N(SiMe )Mes}  ⋅ NHC (3). This adduct reacts further with the Lewis acid BH to yield the Lewis acid-base complex Si {N(SiMe )Mes}  ⋅ NHC  ⋅ BH (4).

Thiophosphonium-Alkyne Cycloaddition Reactions: A Heavy Congener of the Carbonyl-Alkyne Metathesis.

While the metathesis reaction between alkynes and thiocarbonyl compounds has been thoroughly studied, the reactivity of alkynes with isoelectronic main group RE=S compounds is rarely reported and unknown for [RP=S] analogues. We show that thiophosphonium ions, which are the isoelectronic phosphorus congeners to thiocarbonyl compounds, undergo [2 + 2]-cycloaddition reactions with different alkynes to generate 1,2-thiaphosphete ions. The four-membered ring species are in an equilibrium state with the corresponding P=C-C=S heterodiene structure and thus undergo hetero-Diels-Alder reactions with acetonitrile.

Cycloadditions with a Stable Charge-Separated Cyclobutadiene-Type Amido-Substituted Silicon Ring Compound.

Reductive debromination of {N(SiMe ) }SiBr with Rieke magnesium results in the formation of the five-vertex silicon cluster with one bromine substituent Si {N(SiMe ) } Br, 1, and the cyclobutadiene analogue 2 in a 1:1 ratio. The latter features a planar four-membered silicon ring with a charge-separated electronic situation. Two silicon atoms in 2 are trigonal planar and the other two trigonal pyramidal.

Delayed Diagnosis of Congenital Hypothyroidism in a Child with Trisomy 21 and Biotinidase Deficiency and Successful Use of Levothyroxine Sodium Oral Solution.

Endocrine disorders are more common and appear earlier in people with trisomy 21 (T21) than in the general population, with thyroid dysfunction being the most common, including both congenital and acquired hypothyroidism. The treatment for biotinidase deficiency, a condition that occurs in approximately 1 : 110,000 people, is with biotin (vitamin B7) supplementation. However, biotin can interfere with endocrine laboratory assays and cause falsely low thyroid-stimulating hormone (TSH) and elevated free thyroxine (FT4) levels.

The effect of statin treatment on intratumoral cholesterol levels and LDL receptor expression: a window-of-opportunity breast cancer trial.

Background: Deregulated lipid metabolism is common in cancer cells and the mevalonate pathway, which synthesizes cholesterol, is central in lipid metabolism. This study aimed to assess statin-induced changes of the intratumoral levels of cholesterol and the expression of the low-density lipoprotein receptor (LDLR) to enhance our understanding of the role of the mevalonate pathway in cancer cholesterol metabolism.

Methods: This study is based on a phase II clinical trial designed as a window-of-opportunity trial including 50 breast cancer patients treated with 80 mg of atorvastatin/day for 2 weeks, between the time of diagnosis and breast surgery.

Assessment of local coupled cluster methods for excited states of BODIPY/Aza-BODIPY families.

It was previously reported that Laplace transformed local CC2 (LCC2*) provided the best agreement (MAE = 0.145 eV) when comparing vertical excitation energies to experimental λ for a benchmark set of 17 BODIPY/Aza-BODIPY molecules. However, these energies did not agree with values obtained from canonical CC2.

Energetics of non-heme iron reactivity: can ab initio calculations provide the right answer?

We use a variety of computational methods to characterize and compare the hydrogen atom transfer (HAT) and epoxidation reaction pathways for oxidation of cyclohexene by an iron(iv)-oxo complex. Previous B3LYP calculations have led to predictions that both alcohol (from the HAT route) and epoxide should be formed in similar amounts, which was not in agreement with experiment where only the HAT product was observed. We show here that ab initio calculations which can take both static and dynamic correlation into account are needed to explain the experimentally observed dominance of the HAT process.

Oxophosphonium-Alkyne Cycloaddition Reactions: Reversible Formation of 1,2-Oxaphosphetes and Six-membered Phosphorus Heterocycles.

While the metathesis reaction between alkynes and carbonyl compounds is an important tool in organic synthesis, the reactivity of alkynes with isoelectronic main-group RE═O compounds is unexplored. Herein, we show that oxophosphonium ions, which are the isoelectronic phosphorus congeners to carbonyl compounds, undergo [2 + 2] cycloaddition reactions with different alkynes to generate 1,2-oxaphosphete ions, which were isolated and structurally characterized. The strained phosphorus-oxygen heterocycles open to the corresponding heterodiene structure at elevated temperature, which was used to generate six-membered phosphorus heterocycles via hetero Diels-Alder reactions.

Parental Concerns on Short Stature: A 15-Year Follow-Up.

Objectives: To compare parental attitudes about short stature over time and determine possible factors that predict changes in attitudes.

Study Design: At baseline (1993-1994), we surveyed parents about their attitudes regarding their children's height. We compared parents of children (aged 4-15 years) referred to endocrinologists (referred, 154) with those of children with heights <10th percentile seen by pediatricians during regular visits (control, 240).

Statin use, HMGCR expression, and breast cancer survival - The Malmö Diet and Cancer Study.

Statins, commonly used to treat hypercholesterolemia, have also been proposed as anti-cancer agents. The identification of a predictive marker is essential. The 3-hydroxy-3-methylglutaryl-coenzyme-A reductase (HMGCR), which is inhibited by statins, might serve as such a marker.

Ab Initio Calculations for Spin-Gaps of Non-Heme Iron Complexes.

We employed our recently proposed multireference approach CASPT2/CC to calculate the quintet-triplet gaps Δ of a series of non-heme Fe═O species and subsequently used these results to benchmark density functional theory (DFT) as well as two variants of local coupled-cluster approaches (DLPNO-CCSD(T) and LUCCSD(T0)). We showed that current implementations of the local coupled-cluster method are not sufficiently accurate. DLPNO-CCSD(T) systematically overstabilizes the quintet state, whereas LUCCSD(T0) overestimates the triplet one.

Limits of Coupled-Cluster Calculations for Non-Heme Iron Complexes.

In a large variety of studies, the coupled-cluster method with singles, doubles, and perturbative triples (CCSD(T)) is used as a reference for benchmarking the performance of density functional theory (DFT) functionals. In the case of open-shell species, this theory can be applied in different forms depending on the restricted or unrestricted treatment of spin. In this study, we show that these different approaches can produce results which deviate by ∼5 kcal/mol for different species on the potential energy surfaces.

Hybrid Local Molecular Orbital: Molecular Orbital Calculations for Open Shell Systems.

In this work we discuss first applications of the local molecular orbital:molecular orbital (LMOMO) scheme on open-shell systems, focusing on the advantages of isolating the orbital space of (or near) metal centers. We have used as a benchmark ligand exchange reactions, discussing the multireference character observed in local and canonical calculations, the impact of the local domain approximations, and the convergence of the hybrid scheme. After drawing some conclusions on how to build a selection for high level regions, we applied the method to the rate-determining steps in a nitrite reductase catalyzed reaction step.

All That Binds Is Not Gold-The Relative Weight of Aurophilic Interactions in Complex Formation.

Often have you heard that complexes containing close Au(I) contacts are strongly influenced by what has come to be known as aurophilic interactions. In this work, local orbital analysis is carried out to separate competing metallophilic and other weak interactions at the correlated level in three selected molecular crystals. We carefully separate and discuss the different contributions to the total interaction energy of dimers and trimers according to their spatial location, and identify the relative weight in binding.

Modelling absorption and emission of a meso-aniline-BODIPY based dye with molecular mechanics.

Absorption and emission spectra of 8-(4-dimethylaminophenyl)-1,3,5,7-tetramethyl-BODIPY have been calculated using Coupled Cluster (CC) approaches, Time-Dependent Density Functional Theory (TD-DFT) and a QM-informed MM approach. In the case of TD-DFT calculations solvent effects were included using the linear-response (LR), corrected linear response (cLR) and state specific (SS) Polarizable Continuum Model (PCM). We show that range-separated functionals give results in reasonable agreement with coupled cluster methods but both tend to overestimate excitation energies.

Toward Highly Accurate Spin State Energetics in First-Row Transition Metal Complexes: A Combined CASPT2/CC Approach.

In previous work on the performance of multiconfigurational second-order perturbation theory (CASPT2) in describing spin state energetics in first-row transition metal systems [ Pierloot et al. J. Chem.