Metamagnetic transition and a loss of magnetic hysteresis caused by electron trapping in monolayers of single-molecule magnet Tb2@C79N.

Realization of stable spin states in surface-supported magnetic molecules is crucial for their applications in molecular spintronics, memory storage or quantum information processing. In this work, we studied the surface magnetism of dimetallo-azafullerene Tb2@C79N, showing a broad magnetic hysteresis in a bulk form. Surprisingly, monolayers of Tb2@C79N exhibited a completely different behavior, with the prevalence of a ground state with antiferromagnetic coupling at low magnetic field and a metamagnetic transition in the magnetic field of 2.5-4 T. Monolayers of Tb2@C79N were deposited onto Cu(111) and Au(111) by evaporation in ultra-high vacuum conditions, and their topography and electronic structure were characterized by scanning tunneling microscopy and spectroscopy (STM/STS). X-ray photoelectron spectroscopy (XPS), in combination with DFT studies, revealed that the nitrogen atom of the azafullerene cage tends to avoid metallic surfaces. Magnetic properties of the (sub)monolayers were then studied by X-ray magnetic circular dichroism (XMCD) at the Tb-M4,5 absorption edge. While in bulk powder samples Tb2@C79N behaves as a single-molecule magnet with ferromagnetically coupled magnetic moments and blocking of magnetization at 28 K, its monolayers exhibited a different ground state with antiferromagnetic coupling of Tb magnetic moments. To understand if this unexpected behavior is caused by a strong hybridization of fullerenes with metallic substrates, XMCD measurements were also performed for Tb2@C79N adsorbed on h-BN|Rh(111) and MgO|Ag(100). The co-existence of two forms of Tb2@C79N was found on these substrates as well, but magnetization curves showed narrow magnetic hysteresis detectable up to 25 K. The non-magnetic state of Tb2@C79N in monolayers is assigned to anionic Tb2@C79N- species with doubly-occupied Tb-Tb bonding orbital and antiferromagnetic coupling of the Tb moments. A charge transfer from the substrate or trapping of secondary electrons are discussed as a plausible origin of these species.

Corrigendum to "Clinical Presentation, Natural History, and Therapeutic Approach in Patients with Solitary Fibrous Tumor: A Retrospective Analysis".

[This corrects the article DOI: 10.1155/2020/1385978.].

Clinical Presentation, Natural History, and Therapeutic Approach in Patients with Solitary Fibrous Tumor: A Retrospective Analysis.

BACKGROUND: Solitary fibrous tumor (SFT) is a rare variant of soft tissue sarcoma (STS). Materials and Methods. We reviewed SFT patients (pts) treated at our institution between 12/1990 and 09/2017. RESULTS: We identified 94 pts with a median follow-up (mFU) of 4.7 years (range: 0.1-21.53). Primary sites were the chest (33%), abdomen (21.3%), brain (12.8%), and extremities (9.6%); 6.4% of pts presented with synchronous metastasis. Median overall survival (mOS) from the first diagnosis was 56.0 months (m) (0.3-258.3). Doege-Potter syndrome was seen in 2.1% of pts. Primary resection was performed in 86 pts (91.5%). Median progression-free survival was 34.1 m (1.0-157.1), and 43% of pts stayed SFT-free during FU. Local recurrence occurred in 26.7% after a mFU of 35.5 m (1.0-153.8), associated with an OS of 45.1 m (4.7-118.2). Metachronous metastasis occurred in 30.2% after a mFU of 36.0 m (0.1-157.1). OS in metastatic pts was 19.0 m (0.3-149.0). Systemic therapy was given to 26 pts (27.7%) with inoperable/metastatic disease. The most common (57.7%) upfront therapy was doxorubicin, achieving responses in 13.3% of pts with a PFS of 4.8 m (0.4-23.8). In second line, pts were treated with ifosfamide or pazopanib, the latter achieving the highest response rates. Third-line treatment was heterogeneous. CONCLUSION: SFT is an orphan malignancy with a highly variable clinical course and a considerable risk of local failure and metachronous metastasis. Surgery is the only curative option; palliative systemic therapy is used in inoperable/metastatic cases but achieves low response rates. The highest response rates are seen with pazopanib in second/third line.

Vitamin D supplementation in cutaneous malignant melanoma outcome (ViDMe): a randomized controlled trial.

BACKGROUND: Previous studies have investigated the protective effect of vitamin D serum levels, at diagnosis and during the follow-up period after treatment, on melanoma outcome. In the present study we assess whether vitamin D supplementation, in the follow-up period after diagnosis and surgical resection of the primary tumor, has a protective effect on relapse of cutaneous malignant melanoma and whether this protective effect correlates with vitamin D levels in serum and Vitamin D Receptor immunoreactivity in the primary tumor. METHODS/DESIGN: This study is a multicenter randomized double blind placebo- controlled phase III trial. Patients between the age of 18 and 80 years diagnosed and treated surgically for a melanoma stage IB-III are eligible for randomization in a 1:1 ratio to active treatment or placebo. The study drug is taken each month and consists of either 100,000 International Unit cholecalciferol or arachidis oleum raffinatum used as a placebo. The primary endpoint is relapse free survival. The secondary endpoints are 25 hydroxyvitamin D3 serum levels at diagnosis and at 6 month intervals, melanoma subtype, melanoma site and stage of melanoma at diagnosis according to the 2009 American Joint Committee on Cancer melanoma staging and classification. At randomization a bloodsample is taken for DNA analysis. The study is approved by the local Ethics Committees. DISCUSSION: If we can confirm our hypothesis that vitamin D supplementation after removal of the tumor has a protective effect on relapse of cutaneous malignant melanoma we may reduce the burden of CMM at several levels. Patients, diagnosed with melanoma may have a better clinical outcome and improved quality of life. There will be a decrease in health care costs related to treatment of metastatic disease and there will be a decrease in loss of professional years, which will markedly reduce the economic burden of the disease. TRIAL REGISTRATION: Clinical Trial.gov, NCT01748448 , 05/12/2012.

Diagnostic accuracy of the Catheter Injection and Aspiration (CINAS) classification for assessing the function of totally implantable venous access devices.

PURPOSE: Intravenous catheters are used for the administration of intravenous therapy and for blood sampling. These devices are considered as well-functioning if both the injection and aspiration are easy. Malfunction is frequently observed and usually vaguely described as occlusion. We developed the CINAS, the Catheter Injection and Aspiration scheme. The CINAS is a catheter function classification tool, which classifies both the injection and the aspiration ability in a uniform way. Each CINAS class consists of a combination of an injection (IN) and an aspiration (AS) code: e.g. IN1AS1 is the CINAS class for a well-functioning catheter. In this series, we aimed to determine the accuracy of the CINAS class reported by nurses, after minimal training, versus a trained researcher, acting as a reference standard. METHODS: Catheter function was assessed during a standard blood sampling procedure through a totally implantable venous access device in a convenience sample of 150 oncology patients. One nurse researcher and 111 oncology nurses both scored the catheter function according to the CINAS classification scheme, independently. Concordance between the scores was calculated. RESULTS: For the 140 catheters scored as well-functioning (IN1AS1 score) by the researcher, 139 or 99.3 % (95 % confidence interval (CI) 96.1-99.9 %) were scored correctly by the nurse participants. Nine out of ten or 90 % (95 % CI 55.5-98.3 %) of malfunctioning catheters (researcher scores different from IN1AS1) were also identified as malfunctioning by the nurse participants and received exactly the same CINAS score in eight cases (80 %, 95 % CI 44.4-97.5 %). The overall accuracy of the CINAS scored by the nurse participants versus the researcher is (139 + 9)/150 or 98.7 % (95 % CI 95.3-99.8 %). CONCLUSIONS: Nurse participants were able to classify the catheter function of totally implantable venous access devices with the CINAS accurately after a brief explanation about the classification options.

Cutaneous adverse effects of BRAF inhibitors in metastatic malignant melanoma, a prospective study in 20 patients.

BACKGROUND: BRAF inhibitors frequently cause significant cutaneous adverse reactions. OBJECTIVE: To study the timing, prevalence and response to treatment of skin lesions in patients receiving V-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors. METHODS: We prospectively studied the cutaneous side-effects of patients with a BRAF mutant (V600E, V600K, V600R) metastatic malignant melanoma treated with a BRAF inhibitor. We systematically registered prevalence, timing of onset and response to treatment. RESULTS: Twenty patients were treated for 2-52 weeks with a BRAF inhibitor. Eleven patients on vemurafenib (58%) developed cutaneous side-effects and 10 patients (42%) had more than one cutaneous adverse event. Verrucous papillomas were observed in eight patients (42%), after 1-12 weeks. We diagnosed four keratoacanthomas in two patients (11%) after 6-10 weeks and two squamous cell carcinomas in two patients (11%) after 10-16 weeks. Seven patients (37%) developed a hyperkeratotic, folliculocentric eruption after 2-8 weeks, resolving quickly under topical steroids. Four patients (21%) presented a facial erythema, two patients (11%) a seborrhoeic dermatitis-like eczema on the scalp. Three patients (16%) developed cystic lesions after 2-11 weeks. Three patients (16%) presented a hand-foot skin reaction after 4-6 weeks, which was successfully treated with topical steroids and keratolytics. Hyperkeratosis of the nipples was seen in one patient (5%). We observed phototoxic reactions after UV exposure in five patients (26%) and alopecia in two patients (11%) after 8-10 weeks. One patient on dabrafenib developed curly hairs (24 weeks), keratotic papules (1 and 36 weeks), a keratoacanthoma (4 weeks) and a hand-foot skin reaction (31 weeks). CONCLUSION: Multiple cutaneous toxicities were observed in patients under BRAF inhibitors, mostly well controlled with adequate treatment. We recommend a multidisciplinary approach with regular assessments of the skin by a dermatologist. This allows early identification and adequate treatment to avoid premature discontinuation of a life-prolonging therapy.

Comparing normal saline versus diluted heparin to lock non-valved totally implantable venous access devices in cancer patients: a randomised, non-inferiority, open trial.

BACKGROUND: Heparin has been used for years as a locking solution in totally implantable venous access devices. Normal saline (NS) might be a safe alternative for heparin. However, evidence of non-inferiority of NS versus heparin is lacking. PATIENTS AND METHODS: We randomly allocated 802 cancer patients with a newly inserted port either to heparin lock (300 U/3 ml) or to NS lock groups in a 1:1 assignment ratio. The primary outcome was the number of functional complications, which was defined as 'easy injection, impossible aspiration' at port access. Secondary outcomes included all functional problems and catheter-related bacteraemia. We hypothesised that NS locks do not cause more functional problems and catheter-related bacteraemia than heparin locks. Non-inferiority is established if the upper limit of the confidence interval (CI) for the relative risk of NS versus heparin is <1.4. RESULTS: Three hundred and eighty-two patients from the NS group and 383 from the heparin lock group were included in the analysis. The incidence rate of our primary outcome (easy injection, impossible aspiration) was 3.70% (95% CI 2.91%-4.69%) and 3.92% (95% CI 3.09%-4.96%) of accesses in the NS and heparin groups, respectively. The relative risk was 0.94% (95% CI 0.67%-1.32%). Catheter-related bloodstream infection was 0.03 per 1000 catheter days in the NS group and 0.10 per 1000 catheter days in the heparin group. CONCLUSION: NS is a safe and effective locking solution in implantable ports if combined with a strict protocol for device insertion and maintenance.

Topological signatures in the electronic structure of graphene spirals.

Topology is familiar mostly from mathematics, but also natural sciences have found its concepts useful. Those concepts have been used to explain several natural phenomena in biology and physics, and they are particularly relevant for the electronic structure description of topological insulators and graphene systems. Here, we introduce topologically distinct graphene forms - graphene spirals - and employ density-functional theory to investigate their geometric and electronic properties. We found that the spiral topology gives rise to an intrinsic Rashba spin-orbit splitting. Through a Hamiltonian constrained by space curvature, graphene spirals have topologically protected states due to time-reversal symmetry. In addition, we argue that the synthesis of such graphene spirals is feasible and can be achieved through advanced bottom-up experimental routes that we indicate in this work.

Bonding between strongly repulsive metal atoms: an oxymoron made real in a confined space of endohedral metallofullerenes.

Endohedral metallofullerenes (EMFs) are able to encapsulate up to four metal atoms. In EMFs, metal atoms are positively charged because of the electron transfer from the endohedral metal atoms to the carbon cage. It results in the strong Coulomb repulsion between the positively charged ions trapped in the confined inner space of the fullerene. At the same time, in many EMFs, such as Lu(2)@C(76), Y(2)@C(79)N, M(2)@C(82) (M = Sc, Y, Lu, etc.), Y(3)@C(80), or Sc(4)O(2)@C(80), metals do not adopt their highest oxidation states, thus yielding a possibility of the covalent metal-metal bonding. In some other EMFs (e.g., La(2)@C(80)), metal-metal bonding evolves as the result of the electrochemical or chemical reduction, which leads to the population of the metal-based LUMO with pronounced metal-metal bonding character. This article highlights different aspects of the metal-metal bonding in EMFs. It is concluded that the valence state of the metal atoms in dimetallofullerenes is not dependent on their third ionization potential, but is determined by their ns(2)(n- 1)d(1)→ns(1)(n- 1)d(2) excitation energies. Peculiarities of the metal-metal bonding in EMFs are described in terms of molecular orbital analysis as well as topological approaches such as Quantum Theory of Atoms in Molecules and Electron Localization Function. Interplay of Coulomb repulsion and covalent bonding is analyzed in the framework of the Interacting Quantum Atom approach.

Nanoscale ear drum: graphene based nanoscale sensors.

The difficulty in determining the mass of a sample increases as its size diminishes. At the nanoscale, there are no direct methods for resolving the mass of single molecules or nanoparticles and so more sophisticated approaches based on electromechanical phenomena are required. More importantly, one demands that such nanoelectromechanical techniques could provide not only information about the mass of the target molecules but also about their geometrical properties. In this sense, we report a theoretical study that illustrates in detail how graphene membranes can operate as nanoelectromechanical mass-sensor devices. Wide graphene sheets were exposed to different types and amounts of molecules and molecular dynamic simulations were employed to treat these doping processes statistically. We demonstrate that the mass variation effect and information about the graphene-molecule interactions can be inferred through dynamical response functions. Our results confirm the potential use of graphene as a mass detector device with remarkable precision in estimating variations in mass at the molecular scale and other physical properties of the dopants.

Feasibility and safety of endovascular stripping of totally implantable venous access devices.

PURPOSE: To evaluate the safety and feasibility of percutaneous stripping of totally implantable venous access devices (TIVAD) in case of catheter-related sleeve and to report a technique to free the catheter tip from vessel wall adherence. MATERIALS AND METHODS: A total of 37 stripping procedures in 35 patients (14 men, 40%, and 21 women, 60%, mean age 53±14 years) were reviewed. Totally implantable venous access devices were implanted because of malignancy in most cases (85.7%). Catheter-related sleeve was confirmed as cause of persistent catheter dysfunction despite instillation of thrombolytics. A technique to mobilize the catheter tip from the vessel wall was used when stripping with the snare catheter was impossible. Technical success, complication rate, and outcome were noted. RESULTS: A total of 55.9% (n=19) of the 34 technically successful procedures (91.9%) could be done with the snare catheter. In 15 cases (44.1%), additional maneuvers to free the TIVAD's tip from the vessel wall were needed. Success rate was not significantly lower before (72.4%) than after (96.7%) implementation of the new technique (P=0.09). No complications were observed. Follow-up was available in 67.6% of cases. Recurrent catheter dysfunction was found in 17 TIVADs (78.3%) at a mean of 137.7 days and a median of 105 days. CONCLUSIONS: Stripping of TIVADs is technically feasible and safe, with an overall success rate of 91.9%. Additional endovascular techniques to mobilize the distal catheter tip from the wall of the superior vena cava or right atrium to allow encircling the TIVAD tip with the snare catheter may be needed in 44.1% of cases.

Organometallic complexes of graphene: toward atomic spintronics using a graphene web.

Graphene|metal|ligand systems open a new realm in surface magnetochemistry. We show that by trapping metal atoms in the two-dimensional potential lattice of a graphene-ligand interface it is possible to build a chemical analogue of an optical lattice, a key setup in quantum information and strongly correlated systems. Employing sophisticated first-principles calculations, we studied electronic and dynamic properties of graphene|metal|ligand assemblies and showed that there is a general principle--spin-charge separation in π-d systems--that underlies the possibility of synthesizing and controlling such systems. We find that ligands can work as a local gate to control the properties of trapped metal atoms and can impose bosonic or fermionic character on such atomic nets, depending on the ligand's nature. Remarkably, the magnetization energy in such systems reaches record-high values of ca. 400 meV, which makes the respective magnetic phenomena utilizable at room temperature. Accompanied by spin polarization of the graphene π-conjugated system it leads to spin-valve materials and brings the realization of quantum computing one step closer.

Lymph node biopsies in a general internal medicine department: algorithm or individualized decision-making?

BACKGROUND: Lymphadenopathy (LA) imposes a diagnostic challenge in internal medicine. Exclusion of malignancy is the primary concern. METHODS: A retrospective case series, including 40 adult patients from the general internal medicine department who underwent lymph node biopsy (LNB) at a single university hospital. Demographics, clinical data and histopathological diagnoses were registered. By means of the latest medical record, we obtained a final diagnosis for each patient and subsequently searched for variables correlated with malignancy. Follow-up was at least one year in 95% of cases. RESULTS: The prevalence of malignancy was 58%. Older age (p = 0.02) was significantly correlated with malignancy. The presence of painful lymphadenopathy at clinical examination (p = 0.02) was significantly associated with a benign outcome. No single or combination of baseline variables satisfactorily excluded malignancy. Histopathological analysis correctly predicted malignancy in 93% of cases. In two cases, an initial diagnosis of benign non-specific lymphadenopathy was reversed to non-Hodgkin lymphoma. In one case the pathological diagnosis was inconclusive. CONCLUSION: Rather than following a universal algorithm to determine the need for LNB in patients with LA, we call for individualized decision-making in each case, carefully appreciating all available information. Additionally, one should keep in mind that false-negative results occur due to sampling errors. Therefore, a minimal number of cases should end with a final diagnosis of benign non-specific lymphadenopathy. Intensive, multidisciplinary cooperation with surgeon and pathologist is needed. Moreover, clinical follow-up should be at least one year.

A Multibox Splitting Scheme: Robust Approximation For ab Initio Molecular Dynamics.

In this work, the multibox (M-box) simulation scheme is introduced, which can be considered as a generalization of the QM/MM scheme for multifragment (molecular) systems. This scheme exploits the natural locality of multifragment molecular-based systems by mapping the system into force-coupled block subspaces. Where defined in this way, the entire system can be fully modeled under a quantum mechanical force field. This allows the description of each subspace explicitly by means of a robust electronic structure theory without the requirement for large computational resources. An adequate block-to-block coupling by means of shared subsystem fragments is applied to preserve the long-distance structural correlation in the system during a molecular dynamic (MD) simulation. Since electronic structure descriptions play a central role in the formulation of several parametric models for charge or energy transport, we expect that this space-time correlated scheme can become a reliable computational tool for charge/energy transport/transfer applications. The efficiency of the method is demonstrated by performing statistical and time-resolved analysis using both the multifragment box and full ab initio approaches. We illustrate the method using as examples the melting process of a one-dimensional benzene chain (weak interaction situation) and NVE dynamics for the CnHn polymeric chain (strong interaction situation). We also have extended the threshold of applicability of our model, demonstrating how it can cope with MD simulation with more complex systems and processes.

Smooth and jump-like metal-dielectric transitions in single-walled carbon nanotubes under functionalization.

We examine at the DFT level of theory the topology of side wall functionalization of the (5,5)metallic single-wall carbon nanotube (CNT) with carbenes (>CX(2)) and its effect on electronic properties of the system. It is demonstrated that specific substructures/topology known to stabilize functionalized fullerene molecules can play the same role in CNTs, as well. Upon deepening of functionalization, "uniformity" of addition motives and related continuous changes in properties transform into regular addition patterns with isolated aromatic islands on the nanotube backbone that give rise to jump-like changes in electronic structure.

Theoretical study of isomerization mechanisms in fluorinated fullerene derivatives.

Various candidate processes that can effect rearrangement of the shell of addends are being discussed for C(60)F(x) and C(60)(CF(3))(y) compounds. It is shown that isomerization of fluorofullerenes is catalyzed by other fullerene molecules or organic donors, while in trifluoromethylated fullerenes such catalysis is inefficient. These observations afford an explanation for important differences between fluorides and CF(3) derivatives of C(60) in distribution of products of their high-temperature syntheses.

Radiation-induced sarcoma: analysis of 46 cases.

A retrospective analysis was performed of 46 cases of sarcoma treated in our institution between 1989 and 2007 that occurred in a previously irradiated area. Eight male and 38 female patients had received radiotherapy, mainly for breast cancer and genitourinary tumours. The interval between irradiation and the diagnosis of sarcoma ranged from 1 to 54 years (median 15 y). The most common clinical findings were a mass, pain and skin dislocation. Angiosarcoma and sarcoma non-otherwise-specified were the most common histological types. Surgical resection was performed in 34 patients (74%) and 5-year survival was 45% when a radical resection was obtained. No 5-year survival was noticed after non-radical resection and in the absence of surgery. Stage and location of the sarcoma were other prognostic factors. Overall 5-year survival was 27% for the whole group.

Functional evaluation of conventional 'Celsite' venous ports versus 'Vortex' ports with a tangential outlet: a prospective randomised pilot study.

GOAL OF WORK: Totally implantable venous access ports are widely accepted in cancer patient treatment, but withdrawal occlusion (WO) can hamper the use of the device. A newly designed Vortex VX port, with a tangential outlet, should allow better clearance of the chamber, thereby reducing occlusion of the device. The present study compared the Vortex port to the classically shaped Celsite port with regards to functional complications. MATERIALS AND METHODS: Two hundred cancer patients were included in a prospective, randomised controlled trial and randomly assigned to the implantation of a Vortex or a Celsite port. Insertion details such as used vein, catheter tip position and infusion or aspiration abilities were recorded. Data were collected concerning ease of access, and functional evaluation was performed each time the port was accessed, regarding the ability to infuse fluids with a syringe and to withdraw blood by measuring the filling time of a Vacutainer blood tube. MAIN RESULTS: Ninety-nine patients received a Celsite port, and 101 had a Vortex port. Demographic variables and insertion details were comparable in both groups. All functional complications, including WO, total occlusion, sluggish inflow and sluggish withdrawal, were higher in the Celsite group (16.12%) than in the Vortex group (11.36%). This difference was not statistically significant. CONCLUSIONS: This study revealed that functional problems occurred less frequently in Vortex compared to Celsite ports. Differences were small and not significant, which indicates that functional problems may be related to other factors.

Quality of life and disability after ilio-inguinal lymphadenectomy.

AIM: To examine and report the quality of life together with the level of disability of cancer patients who underwent therapeutic ilio-inguinal lymphadenectomy. MATERIALS AND METHODS: The complete files of 62 patients who underwent 66 procedures between January 1990 and November 2006 were obtained and analysed retrospectively. Data concerning postoperative complications, presence and extent of lymphoedema, physical symptoms, duration of disability, daily life and social activities were collected through a specific questionnaire and reviewed. RESULTS: Early postoperative complications occurred in 36% of cases. Sixty-five percent of patients developed some degree of postoperative lymphoedema. Twenty patients suffered at least one episode of erysipelas. Median postoperative disability was 4 months (range 1.5 to 24 months). Among the active population, 8 patients (18%) never returned to work. Postoperative quality of life was good or very good for most patients, with acceptable limitation in daily activities. CONCLUSION: Ilio-inguinal lymphadenectomy is the only radical procedure able to provide long-term tumour control and maintain a good to very good quality of life, thus providing a real possibility of returning to work.