Metal Cage Research Articles

Nitriding of AISI 1020 steel: comparison between conventional nitriding and nitriding with cathodic cage

Cylindrical samples of AISI 1020 steel were nitrided, using the techniques of conventional plasma nitriding and cathodic cage. In the latter, the samples are kept at floating potential, inside of a cage that works as a cathode and to shield the samples from the cathodic potential. A systematic study was conducted in order to evaluate the efficiency of this technique in the elimination of edge effect, in comparison with conventional plasma nitriding. In addition, another comparative study of the phases obtained using the conventional plasma nitriding and nitriding with cathodic cage was performed. Two metallic cages were used, one made of austenitic stainless AISI 316 and other one made of AISI 1020 steel, to prove the effect of deposition in nitriding with cathodic cage. The samples which were nitrided by this new technique had shown nitriding rates, crystalline phases, and microhardness, similar to those samples which were nitrided conventionally. However, it was possible to confirm the elimination of edge effect through the characterization by optical microscopy and by microhardness test along the samples surfaces. The samples were characterized by optical microscopy, microhardness tests and X-ray diffraction.

No more metallic cages: An attractive hybrid strategy with bioresorbable vascular scaffold and drug-eluting balloon for diffuse or tandem lesions in the same vessel

Pre-dilation before BVS or DEB use 8 (100) 8 (100) BVS or DEB diameter, mm 2.9 ± 0.3 2.5 ± 0.2 BVS or DEB length, mm 27.5 ± 11.8 28.1 ± 9.3 Post-dilation 8 (100) Max. balloon diameter, mm 3.1 ± 0.4 Max. balloon pressure, atm. 21.0 ± 3.2 Pre-procedural QCA RVD, mm 2.7 ± 0.4 2.2 ± 0.3 MLD, mm 0.7 ± 0.6 0.7 ± 0.6 %DS 86.9 ± 10.3 82.3 ± 12.5 Lesion length, mm 24.8 ± 6.2 20.1 ± 7.1 Post-procedural QCA RVD, mm 3.0 ± 0.4 2.4 ± 0.3 MLD, mm 2.8 ± 0.4 2.2 ± 0.3 %DS 6.9 ± 4.5 10.7 ± 6.2 Acute gain, mm 2.1 ± 0.6 1.5 ± 0.3 The everolimus-eluting ABSORB bioresorbable vascular scaffold (BVS) (Abbott Vascular, Santa Clara, California) has emerged as an attractive alternative to conventional metallic stents for the treatment of coronary artery disease. Currently, BVS use is expanding from simple to more complex lesions despite technical challenges encountered [1–5]. On the other hand, drug-eluting balloons (DEB) have already been associated with favorable outcomes after treatment of baremetal stent restenosis or small vessel disease [6–8]. Of note, the common advantage of these 2 devices when used together, is the fact that no metallic cages are left behind after their usage (“hybrid strategy”), which could potentially have long-term benefits for the vessel such as restoration of endothelial function, vascular healing and positive remodeling. In this article, we report our preliminary results after treatment of diffuse or tandem lesions in the same coronary artery with the afore-mentioned “hybrid strategy”. Between May 2012 and December 2013, 195 patients were treated with BVS at 3 centers (EMO-GVM Centro Cuore Columbus, San Raffaele Scientific Institute, Milan, Italy and Azienda Ospedaliera “Bolognini”, Seriate (BG), Italy). Of these, 8 patients who underwent BVS implantation for a de novo lesion (proximal ormiddle segment) and DEB inflation for small vessel disease (distal segment) or in-stent restenosis (ISR) in the

The coronary stent story

The objective of this article is to narrate the story of stent development as witnessed by the author who was present from the very beginning. By the end of eighties, coronary angioplasty (PTCA) had clearly shown its limitations such as abrupt vessel occlusion, dissection and restenosis rate of up to 35%. The Medinvent Company developed a self-expanding-stent that was implanted in a first series of patients by Ulrich Sigwart in Lausanne, Switzerland in 1986. However, the multicenter study in 1989 had disastrous results, with 25% of stent occlusion rate and restenosis of >20% in remained patients. The Palmaz-Schatz stent was first bare-metal stent (BMS) largely used in the world since 1990. The heavy anticoagulation treatment was abolished by A. Colombo in 1993. By 1997, about 17 new models existed, still the abrupt stent occlusion, subacute stent thrombosis (2-4%), and restenosis (25-30%), were major problems. Drug-eluting stents (DES) were developed to specifically address the problems of restenosis encountered with BMS. The sirolimus eluting stents used since 2002 have shown better clinical results than paclitaxel eluting stents arriving in 2004, but newcomers using zotaralimus, everolimus and biolimus elusions have arrived showing even better results. Currently, the last generation of stent need only 3 months of dual antiplatelet treatment, bioapsorbale coating is only on ab-luminal side of stent, struts are thin and metallic cage is laser cut hypotube. The case of chronic total coronary occlusion is discussed, as this indication benefited most from the stent development. Bioresorbable vascular scaffolds (BVS) are intended to overcome most drawbacks of stents: the presence of a metallic cage, positive remodelling, and normal vasomotor vessel function, but long-term results are still unknown.

Lumbar Lordosis Restoration with an Eight Degree Cage in Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease

Purpose: The purpose of this study is to determine how much lumbar lordosis is restored with an eight degree cage in posterior lumbar interbody fusion (PLIF) for degenerative lumbar spinal disease. Materials and Methods: A total of 61 patients who underwent PLIF using a metal cage with an eight degree lordotic angle were evaluated. Cases with complications such as subsidence of the cage or instrument failure were excluded from this study. Lumbar lordosis, segmental lordosis, disc height, and bony union were analyzed on the patients’ radiographs. Results: Cages were inserted at L3-4 in 17 patients, L4-5 in 54 patients, and L5-S1 in 20 patients. The number of fused level was 1 segment in 32 patients, 2 segments in 27 patients, and 3 segments in 2 patients. The lumbar lordosis was 33.6 before surgery, improved to 37.6 after surgery, and then was changed to 37.0 at the final follow-up. Segmental lordosis at which the cage was inserted was restored after surgery at L4-5 and L5-S1. Disc height was improved with surgery as well. Satisfactory bony fusion was achieved in 95% of the patients. Conclusion: PLIF using an eight degree lordotic cage for degenerative spinal disease resulted in restoration of lumbar lordosis and segmental lordosis, although these angles showed some loss of correction after surgery.

Sc2S@C68: an obtuse di-scandium sulfide cluster trapped in a C2vfullerene cage

The spectrum-detected smallest sulfide clusterfullerene Sc2S@C68 has not been characterized yet. Herein, we explored a series of Sc2S@C68 species to determine which could be the most promising isomer. The results suggest that a sulfide cluster encapsulated in the C2v(6073)-C68 cage which violates the isolated pentagon rule (IPR) with two opposite pentalenes has the lowest energy and an overwhelming thermodynamic stability. Two scandium atoms coordinate with the two opposite pentalenes, leading to an obtuse Sc-S-Sc angle of 151°. The bond lengths of the two Sc-S bonds are equivalent. Frontier molecular orbital distributions exhibit substantial overlaps between metallic orbitals and cage orbitals, indicating that covalent interactions cannot be ignored, which have been unambiguously identified in terms of Mayer bond order and bonding critical point (BCP) indicator methods. Electrochemical properties as well as (13)C NMR, UV-vis-NIR, and IR spectra of Sc2S@C2v(6073)-C68 have been theoretically studied to assist further experimental characterization.

CO2 as a reaction ingredient for the construction of metal cages: a carbonate-panelled [Gd6Cu3] tridiminished icosahedron

A CO3(2-)-panelled [Gd(III)6Cu(II)3] cage conforming to a tridiminished icosahedron is synthesised by bubbling CO2 through a solution of Gd(III) and Cu(II) ions.

Efeitos da forma física da ração e da linhagem de frangos de corte sobre a digestibilidade dos nutrientes e determinação de energia líquida

Para avaliar os efeitos da forma física da ração, do consumo de ração controlado e das linhagens sobre a digestibilidade dos nutrientes, os valores de energia das rações e a produção de calor pelas aves, foram utilizados 210 pintos machos da linhagem Cobb® e 210 pintos machos da linhagem Ross-308®. Os tratamentos foram definidos pela forma física da ração, pelo consumo de ração controlado e pela linhagem, da seguinte forma: ração farelada à vontade, ração peletizada à vontade e ração peletizada controlada com consumo igual ao da ração farelada. O delineamento experimental foi o de blocos ao acaso, em arranjo fatorial 3x2 (três rações e duas linhagens), com quatro repetições (períodos), sendo o período considerado como bloco. A digestibilidade da matéria seca não foi afetada pela forma física da ração, entretanto a digestibilidade do extrato etéreo melhorou com a peletização. A linhagem influenciou a digestibilidade dos nutrientes e juntamente com a forma física da ração afetou a produção de calor das aves. A utilização de rações peletizadas aumentou os valores de energia líquida das rações, independentemente da linhagem, favorecendo o desempenho de frangos de corte.

Indoor and Deep Sub-Tidal Intermediate Culture of Trochus niloticus for Restocking

The high demand for shells of the large reef-associated gastropod Trochus niloticus in the manufacture of mother-of-pearl buttons has resulted in a widespread decline of its population. As a consequence, juvenile mass production and restocking has been practiced as one of the many conservation measures. Trochus has long been successfully bred in captivity, but culturing of juveniles until ready for release is faced with many problems, including the shortage of natural food. Terrestrial plants have traditionally been used by fishermen as food in keeping wild trochus juveniles, but their potential use in intermediate culture of trochus has not been evaluated. We conducted four growth trials for 60–120 days, rearing hatchery-produced juveniles (10–28-mm shell diameter) at different stocking densities in indoor tanks and sea cages, with coconut leaves as the main or an additional substrate. An average growth rate of 4.4 mm mo−1 (95% CL 4.0–4.7 mm mo−1) for all stocking densities was achieved in growth trials using small cages deployed at 5–6 m on the reef slope, which was comparable to growth rates in the wild. This growth rate was three times higher than in trials using large metal cages on the reef slope, and 2 to 23 times higher than indoor trials using wooden tanks or small cages in concrete tanks. Survival rates were as high as 99%. Incidence of escape in sub-tidal cages was low except when some cages were damaged by strong waves. The results indicate that trochus juveniles can be successfully cultured at high density in sub-tidal cages with coconut leaves as substrate.

Comparison of anterior cervical fusion by titanium mesh cage versus nano-hydroxyapatite/polyamide cage following single-level corpectomy

The titanium mesh cage (TMC) is a typical metal cage device which has been widely used in cervical reconstruction for decades. Nano-hydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel biomimetic non-metal cage device growing in popularity in many medical centres in recent years. There has been no comparison of the efficacy between these two anterior reconstructing cages. The purpose of this study was to compare the radiographic and clinical outcomes of these two different devices. Sixty-seven eligible patients with single-level ACCF using TMC or n-HA/PA66 cage for cervical degenerative diseases, with four-year minimum follow-up, were included in this prospective non-randomised comparative study. Their radiographic (cage subsidence, fusion status, segmental sagittal alignment [SSA]) and clinical (VAS and JOA scales) data before surgery and at each follow-up was recorded completely. The fusion rate of the n-HA/PA66 group was higher than TMC at one year after surgery (94% vs. 84%) though their finial fusion rates were similar (97% vs. 94%). Finial n-HA/PA66 cage subsidence was 1.5 mm with 6% of severe subsidence over three millimetres, which was significantly lower than the respective 2.9 mm and 22% of TMC (P < 0.0001). Lastly, SSA, VAS and JOA in TMC group were worse than in the n-HA/PA66 group (P = 0.235, 0.034 and 0.007, respectively). The n-HA/PA66 cage is associated with earlier radiographic fusion, less subsidence and better clinical results than TMC within four years after one-level ACCF. With the added benefit of radiolucency, the n-HA/PA66 cage may be superior to TMC in anterior cervical construction.

PB29 液晶基で修飾されたかご状金属錯体の構築(化学・材料,ポスター発表,2013年日本液晶学会討論会)

PB29 液晶基で修飾されたかご状金属錯体の構築(化学・材料,ポスター発表,2013年日本液晶学会討論会)

The CASCADE trial: effectiveness of ceramic versus PEEK cages for anterior cervical discectomy with interbody fusion; protocol of a blinded randomized controlled trial

BackgroundAnterior cervical discectomy with interbody fusion cages is considered the standard surgical procedure in patients with cervical disc herniation. However, PEEK or metal cages have some undesirable imaging characteristics, leading to a search for alternative materials not creating artifacts on images; silicon nitride ceramic. Whether patients treated with silicon nitride ceramic cages have similar functional outcome as patients treated with PEEK cages is not known. We present the design of the CASCADE trial on effectiveness of ceramic cages versus PEEK cages in patients with cervical disc herniation and/or osteophytes.Methods/DesignPatients (age 18–75 years) with monoradicular symptoms in one or both arms lasting more than 8 weeks, due to disc herniation and/or osteophytes, are eligible for the trial. The study is designed as a randomized controlled equivalence trial in which patients are blinded to the type of cage for 1 year. The total follow-up period is 2 years. The primary outcome measure is improvement in the Neck and Disability Index (NDI). Secondary outcomes measures include improvement in arm pain and neck pain (VAS), SF-36 and patients' perceived recovery. The final elements of comparison are perioperative statistics including operating time, blood loss, length of hospital stay, and adverse events. Lateral plane films at each follow-up visit and CT scan (at 6 months) will be used to judge fusion and the incidence of subsidence. Based on a power of 90% and assuming 8% loss to follow-up, 100 patients will be randomized into the 2 groups. The first analysis will be conducted when all patients have 1 year of follow-up, and the groups will be followed for 1 additional year to judge stability of outcomes.DiscussionWhile the new ceramic cage has received the CE Mark based on standard compliance and animal studies, a randomized comparative study with the golden standard product will provide more conclusive information for clinicians. Implementation of any new device should only be done after completion of randomized controlled effectiveness trials.

Update on Drug-Eluting Balloons for Percutaneous Coronary Interventions

Restenosis prevention continues to be a challenge to the interventional cardiologist. The introduction of stents has virtually eliminated the problems of elastic recoil, late negative remodelling and scaffolds unpredictable dissections, leaving neointimal hyperplasia as the primary cause of restenosis. Drug-eluting stents (DES), using antiproliferative drugs added to stents, serve to prevent the development of neointima hyperplasia. However, they can be associated with an irregular endothelialisation, requiring prolonged double antiplatelet therapy to reduce the risk of late and very late stent thrombosis. Moreover, incomplete suppression of neointimal hyperplasia at the stent margins or between the struts may limit the efficacy of DES, especially when they are used “off-label” in complex clinical and anatomic settings. Drug-eluting balloons (DEBs) may represent a therapeutic alternative for the interventional treatment of coronary disease. With the use of this technology, the short-term transfer of antiproliferative drugs to the arterial wall appears feasible, thus potentially reducing the untoward effects of the prolonged drug release associated with polymer-based stent technologies, and avoiding the risk associated with having a permanent metallic cage. In the last few years, research in this field has been increasing, and several trials have already been published or are planned to determine the place in therapy of these devices. The present article will review the available in vitro, animal and human evidence regarding these devices at present, and discuss the emerging role and their future perspectives.

ChemInform Abstract: Anion Recognition by Coordinative Interactions: Metal—Amine Complexes as Receptors

AbstractReview: 72 refs.

Gold Nanocage‐Based Dual Responsive “Caged Metal Chelator” Release System: Noninvasive Remote Control with Near Infrared for Potential Treatment of Alzheimer's Disease

AbstractMetal ions have been demonstrated to participate in the pathology of Alzheimer's disease (AD): amyloid‐β peptide (Aβ) aggregation and formation of neurotoxic reactive oxygen species (ROS), such as H2O2. Metal chelator can block ROS formation and inhibit metal induced Aβ aggregation. Metal‐ion chelation therapy as a compelling treatment for AD has been extensively studied. However, most chelators are not suitable for AD treatment because of their poor permeability of the blood–brain barrier and their limited ability to differentiate toxic metals associated with Aβ plaques from those associated with normal metal homeostasis. Here, a novel dual‐responsive “caged metal chelator” release system based on gold nanocage (AuNC) for AD treatment is reported. Since arylboronic ester is redox‐ and thermal‐sensitive, phenylboronic acid‐functionalized AuNC can serve as an efficient delivery system for H2O2‐responsive controlled release of metal chelator. The release can be further enhanced through remote control with NIR light because of the high near‐infrared absorbance of AuNC. The smart system can effectively inhibit Aβ aggregate formation, decrease cellular ROS, and protect cells from Aβ‐related toxicity. In light of these advantages, this design provides new insights into noninvasive remote control with NIR to improve therapeutic efficacy for treatment of Alzheimer's disease.

Use of Zirconium Dioxide during Fermentation as an Alternative to Protein Fining with Bentonite for White Wines

Zirconia pellets (25 g/L) enclosed in a metallic cage were added on the second day to fermenting Riesling, Sauvignon blanc, and Semillon juices. After 48 hours, the zirconia-treated juices showed a large decrease in protein content and the resulting wines were heat stable. Compared to control juices, the fermentation rate was significantly increased for two juices and unchanged in the other juice. There were reductions in concentration of some mineral elements and tartaric acid and increases in pH in the resulting wines from the zirconia-treated juices.

ChemInform Abstract: New Features in Coordination Chemistry: Valuable Hints from X‐Ray Analyses of Endohedral Metallofullerenes

AbstractReview: 67 refs.

Cage Metal Complexes: Synthesis, X‐ray Structure, and Spectral and Redox Behavior of the First Hybrid Iron(II) Clathrochelatoscorpionate and Its Pyrazoloxime‐Armed Macrocyclic Intermediate (Eur. J. Inorg. Chem. 12/2013)

Cage Metal Complexes: Synthesis, X‐ray Structure, and Spectral and Redox Behavior of the First Hybrid Iron(II) Clathrochelatoscorpionate and Its Pyrazoloxime‐Armed Macrocyclic Intermediate (Eur. J. Inorg. Chem. 12/2013)

Cage Metal Complexes: Synthesis, X‐ray Structure, and Spectral and Redox Behavior of the First Hybrid Iron(II) Clathrochelatoscorpionate and Its Pyrazoloxime‐Armed Macrocyclic Intermediate3

Invited for the cover of this issue is the group of Yan Voloshin at Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences. The image shows the X-ray structure of the first hybrid clathrochelatoscorpionate with an encapsulated iron(II) ion.

PPh3-Derivatives of [Pt3n(CO)6n]2–(n= 2–6) Chini’s Clusters: Syntheses, Structures, and31P NMR Studies

The reaction of the [Pt3n(CO)6n](2-) (n = 2-6) Chini's clusters with increasing amounts of PPh3 has been investigated in detail by combined FT-IR, (31)P{(1)H} NMR, and electrospray ionization-mass spectrometry (ESI-MS) studies, showing that up to three CO ligands are gradually substituted by PPh3, resulting in isonuclear phosphine-substituted anionic clusters of general formula [Pt3n(CO)(6n-x)(PPh3)(x)](2-) (n = 2-6; x = 1-3). Further addition of PPh3 results in the elimination of the neutral Pt3(CO)3(PPh3)3 species and formation of lower nuclearity anionic clusters. [Pt12(CO)22(PPh3)2](2-) and [Pt9(CO)16(PPh3)2](2-) have been structurally characterized, and they maintain the trigonal prismatic structures of the parent homoleptic clusters, with the two PPh3 ligands bonded to different external Pt3-triangles in relative cis-position. Conversely, the crystal structure of [Pt6(CO)10(PPh3)2](2-) shows that its metal cage is transformed from trigonal prismatic to trigonal antiprismatic after CO/PPh3 exchange.

Size matters, so does shape: Inhibition of transcription of T7 RNA polymerase by iron(II) clathrochelates

Coordination and organoelement compounds are rarely proposed as the drug candidates despite their vast potential in the area owing to their strictly controlled geometry and rather extensive surface. This is the first example of the inhibition of transcription in the system of T7 RNA polymerase by cage metal complexes. Their IC50 values reach as low as the nanomolar range, placing them among the most potent metal-based transcription inhibitors.