Alkynes (R
′CCR
″) insert into the μ-carbon–metal bond of diiron complexes affording μ-σ:η
3 vinyliminium species. Several isomers have been found arising from: (i) the iminium moiety configuration ...(
E,
Z), (ii) mutual Cp position (
cis–
trans isomers), (iii) head–head or head–tail insertion mode of R
′CCR
″. These isomeric forms have been investigated by NMR and X-ray diffraction.
Terminal alkynes (HCCR
′) (R
′=COOMe, CH
2OH) insert into the metal–carbyne bond of the diiron complexes Fe
2{μ-CN(Me)(R)}(μ-CO)(CO)(NCMe)(Cp)
2SO
3CF
3 (R=Xyl,
1a; CH
2Ph,
1b; Me,
1c; Xyl=2,6-Me
2C
6H
3), affording the corresponding μ-vinyliminium complexes Fe
2{μ-σ:η
3-C(R
′)CHCN(Me)(R)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (R=Xyl, R
′=COOMe,
2; R=CH
2Ph, R
′=COOMe,
3; R=Me, R
′=COOMe,
4; R=Xyl, R
′=CH
2OH,
5; R=Me, R
′=CH
2OH,
6). The insertion is regiospecific and C–C bond formation selectively occurs between the carbyne carbon and the CH moiety of the alkyne. Disubstituted alkynes (R
′CCR
′) also insert into the metal–carbyne bond leading to the formation of Fe
2{μ-σ:η
3-C(R
′)C(R
′)CN(Me)(R)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (R
′=Me, R=Xyl,
8; R
′=Et, R=Xyl,
9; R
′=COOMe, R=Xyl,
10; R
′=COOMe, R=CH
2Ph,
11; R
′=COOMe, R=Me,
12). Complexes
2,
3,
5,
8,
9 and
11, in which the iminium nitrogen is unsymmetrically substituted, give rise to
E and/or
Z isomers. When iminium substituents are Me and Xyl, the NMR and structural investigations (X-ray structure analysis of
2 and
8) indicate that complexes obtained from terminal alkynes preferentially adopt the
E configuration, whereas those derived from internal alkynes are exclusively
Z. In complexes
8 and
9,
trans and
cis isomers have been observed, by NMR spectroscopy, and the structures of
trans-
8 and
cis-
8 have been determined by X-ray diffraction studies.
Trans to
cis isomerization occurs upon heating in THF at reflux temperature. In contrast to the case of HCCR
′, the insertion of 2-hexyne is not regiospecific: both Fe
2{μ-σ:η
3-C(CH
2CH
2CH
3)C(Me)CN(Me)(R)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (R=Xyl,
13; R=Me,
15) and Fe
2{μ-σ:η
3-C(Me)C(CH
2CH
2CH
3)CN(Me)(R)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (R=Xyl,
14, R=Me,
16) are obtained and these compounds are present in solution as a mixture of
cis and
trans isomers, with predominance of the former.
The implantable gastric stimulator (IGS), a pacemaker-like device, has been found to be safe and effective to induce and maintain weight loss. We present our experience with 20 morbidly obese ...patients.
Between September 20 and November 22, 2002, 20 patients (F/M 12/8), mean age 40.3 years (23-62) underwent IGS implantation. Mean BMI was 40.9 (33.9-48.2), mean weight 115.0 kg (87.0-137.0) and mean excess weight (EW) 51.3 kg (35.6-70.1).Co-morbitidies were: 3 cases of hypertension, 1 diabetes, 1 dislipidemia and 1 depression. Mean operative time was 58.5 min (37-85). The IGS was actived 30 days after implantation. Patients were advised to follow a low calorie diet and behavior modification (to avoid fat and to ingest more liquids during meals, to chew slowly, to eat vegetables before main meals, and to perform exercise daily).
Mean +/- standard error percent excess weight loss (%EWL) was: 10.6+/-1.8 at 1 month; 15.0+/-2.3 at 2 months; 16.6+/-2.6 at 3 months; 18.1+/-3.5 at 4 months; 15.5+/-3.5 at 6 months; 18.9+/-3.5 at 8 months; and 23.8+/-5.0 at 10 months. There were no intra-operative surgical or long-term complications. There were 3 intra-operative gastric penetrations, observed by gastroscopy, without sequelae. One patient with hypertension ceased his medical therapy at the 4th month.
IGS can be implanted laparoscopically with minimal perioperative complications. The observed weight loss is comparable to other noninvasive procedures. If weight loss is maintained, IGS could be considered as a first choice therapy in the treatment of morbid obesity in selected patients.
Retrograde ejaculation (RE) is a condition defined as the backward flow of the semen during ejaculation, and when present can result in male infertility. RE may be partial or complete, resulting in ...either low seminal volume or complete absence of the ejaculate (dry ejaculate). RE can result from anatomic, neurological or pharmacological conditions. The treatment approaches outlined are determined by the cause. Alkalinizing urinary pH with oral medications or by adding sperm wash media into the bladder prior to ejaculation may preserve the viability of the sperm. This article provides a step-by-step guide to diagnose RE and the optimal techniques to retrieve sperm.
In this paper, we investigate the problem of the strategic foundation of the Cournot–Walras equilibrium approach. To this end, we respecify à la Cournot–Walras the mixed version of a model of ...simultaneous, noncooperative exchange, originally proposed by Lloyd S. Shapley. We show, through an example, that the set of the Cournot–Walras equilibrium allocations of this respecification does not coincide with the set of the Cournot–Nash equilibrium allocations of the mixed version of the original Shapley’s model. As the nonequivalence, in a one-stage setting, can be explained by the intrinsic two-stage nature of the Cournot–Walras equilibrium concept, we are led to consider a further reformulation of the Shapley’s model as a two-stage game, where the atoms move in the first stage and the atomless sector moves in the second stage. Our main result shows that the set of the Cournot–Walras equilibrium allocations coincides with a specific set of subgame perfect equilibrium allocations of this two-stage game, which we call the set of the Pseudo–Markov perfect equilibrium allocations.
Objective: Severe obesity represents a serious threat for public health for prevalence, incidence and economic burden. When changes in lifestyle, psychological behavioural therapies or specific ...medicines are not able to improve the clinical picture of patients, bariatric surgery represents the most effective treatment. However, these patients need a careful nutritional surveillance because they are exposed to the risk of nutritional deficit. Supplementations with multivitamin formulations, calcium citrate and vitamin D were performed by nutritionist in the past, to correct the deficits but the results were often ineffective. Recently, several foods for special medical purposes (FSMP) were developed for these cases. The aim of this study is to assess the efficacy of FSMP administration to avoid micronutrients deficiencies, particularly vitamin D and Iron, in post-surgery phase to a sample of patients undergoing bariatric surgery. Patients and Methods: 52 patients undergoing bariatric surgery were enrolled. For each patient, starting from the third day after surgery, one sachet for day of FSMP, containing Vitamins (A, B1, B2, B3, B5, B6, B8, B9, B12, C, D, E, K) and minerals (Iron, zinc, copper, selenium) was administered for three months. Anthropometric parameters, complete blood count, blood levels of folic acid, calcium, parathormone, ferritin, iron serum, transferrin, vitamin B12 and vitamin D were recorded, both at the time of surgery (T0) and after 3 months of FSMP intake (T1). Results: All patients have shown a significative weight loss 3 months after surgery (T1), with reduction of BMI, body fat, white blood cell count, platelets and transferrin. Moreover, at T1, increases of medium corpuscular volume (MCV), iron and vitamin D were observed. Conclusions: Study results highlight that the administration of this FSMP for three months in post-surgery phase of patients underwent bariatric surgery is useful to avoid micronutrients deficiencies, favouring a better adherence to the treatment.
NaBH
4 gives addition at the bridging vinyliminium ligand in the diiron complexes Fe
2{μ-η
1:η
3-C
γ(R′)
C
β (R″)C
α
N(Me)(R)}(μ-CO)(CO)(Cp)
2 SO
3CF
3 (R′ and R″
=
alkyl or aryl substituents, R
=
...Me, CH
2Ph or Xyl). Depending on the nature of these substituents and on the geometry of the parent complexes
cis or
trans, H
− addition occurs selectively at the iminium carbon (C
α) or at the adjacent C
β position, affording complexes of the type
5d or
6a, respectively.
New μ-vinylalkylidene complexes
cis-Fe
2{μ-η
1:η
3-C
γ(R′)C
β(R″)
C
αHN(Me)(R)}(μ-CO)(CO)(Cp)
2 (R
=
Me, R′
=
R″
=
Me,
3a; R
=
Me, R′
=
R″
=
Et,
3b; R
=
Me, R′
=
R″
=
Ph,
3c; R
=
CH
2Ph, R′
=
R″
=
Me,
3d; R
=
CH
2Ph, R′
=
R″
=
COOMe,
3e; R
=
CH
2 Ph, R′
=
SiMe
3, R″
=
Me,
3f) have been obtained b yreacting the corresponding vinyliminium complexes Fe
2{μ-η
1:η
3-C
γ(R′)
C
β(R″)C
α
N(Me)(R)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (
2a–
f) with NaBH
4. The formation of
3a–
f occurs via selective hydride addition at the iminium carbon (C
α) of the precursors
2a–
f. By contrast, the vinyliminium
cis-Fe
2{μ-η
1:η
3-C
γ (R′)
=
C
β(R″)C
α
=
N(Me)(Xyl)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (R′
=
R″
=
COOMe,
4a; R′
=
R″
=
Me,
4b; R′
=
Pr
n
, R″
=
Me,
4c; Pr
n
=
CH
2CH
2CH
3, Xyl
=
2,6-Me
2C
6H
3) undergo H
− addition at the adjacent C
β, affording the bis-alkylidene complexes
cis-Fe
2{μ-η
1:η
2-C(R′)C(H)(R″)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)
2, (
5a–
c). The
cis and
trans isomers of Fe
2{μ-η
1:η
3-C
γ(Et)
C
β(Et)C
α
N(Me)(Xyl)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (
4d) react differently with NaBH
4: the former reacts at C
α yielding
cis-Fe
2{μ-η
1:η
3-C
γ(Et)C
β(Et)
C
αHN(Me)(Xyl)}(μ-CO)(CO)(Cp)
2,
6a, whereas the hydride attack occurs at C
β of the latter, leading to the formation of the bis alkylidene
trans-Fe
2{μ-η
1:η
2-C(Et)C(H)(Et)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)
2 (
5d). The structure of
5d has been determined by an X-ray diffraction study. Other μ-vinylalkylidene complexes
cis-Fe
2{μ-η
1:η
3-C
γ(R′)C
β(R″)
C
αHN(Me)(Xyl)}(μ-CO)(CO)(Cp)
2, (R′
=
R″
=
Ph,
6b; R′
=
R″
=
Me,
6c) have been prepared, and the structure of
6c has been determined by X-ray diffraction. Compound
6b results from treatment of
cis-Fe
2{μ-η
1:η
3-C
γ(Ph)
C
β(Ph)C
α
N(Me)(Xyl)}(μ-CO)(CO)(Cp)
2SO
3CF
3 (
4e) with NaBH
4, whereas
6c has been obtained by reacting
4b with LiHBEt
3. Both
cis-
4d and
trans-
4d react with LiHBEt
3 affording
cis-
6a.
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