Nipple Sparing Goldilocks Mastectomy, A New Modification of the Original Technique.

Objective: Although Goldilocks mastectomy offers good aesthetic outcomes. Removal of the nipple-areolar complex (NAC) often has a negative psychological impact. The objective of this study was to assess the feasibility and esthetic outcome of this technique with salvage of the NAC using a dermal pedicle. Materials and Methods: The study included female patients suffering from breast carcinoma with large and or ptotic breast. Patients were offered Goldilocks mastectomy. Those who were unfit for anesthesia, those with locally advanced or metastatic disease or those refusing the procedure were excluded. Results: Fifteen female patients (18 breasts) with a mean age of 51.6 years underwent Goldilocks breast reconstruction with a trial of NAC preservation. The mean body mass index was 39.1 kg/m2. More than half (56%) were cup C, while 44% were cup D. Seven cases (46.7%) showed grade II ptosis and 8 (53.3%) were grade III. The mean operative time was 168 minutes (range 130-240 minutes). NAC ischemic changes were noted in five cases; two (11%) were partial while three (17%) were total. Two cases (11%) suffered from flap loss and one of them was total. No locoregional recurrence or distant metastases were observed. Conclusion: The Goldilocks mastectomy with nipple preservation is an appealing and feasible option for a certain group of patients who have large-sized and/or ptotic breasts. Nevertheless, it is a time-consuming technique with relatively higher rates of flap and NAC complications. Further, studies are required with a larger number of cases and longer follow-up.

The Evaluation of a Cost-Effective Method for Tumour Marking Prior to Neo-Adjuvant Chemotherapy Using Silver Rods.

Objective: The lack of objective documentation of pre-neoadjuvant chemotherapy (NAC) tumour margins is a major constraint in performing safe breast conserving surgery (BCS) in patients with breast cancer. Using a novel method of marking pre-NACT tumour margins with indigenous silver wire markers, this retrospective observational study attempted to assess the feasibility of safe BCS in breast cancer patients by performing excision wide of the marked pre-NACT margins. Materials and Methods: This retrospective observational study was conducted on breast cancer patients who were attending our oncology centre between May, 2015 and April, 2022. All patients had received NAC followed by surgery as recommended by our multidisciplinary team. All the patients had a primary operable solitary breast cancer. We used radiopaque metallic rods made from silver to localize tumour margins prior to NAC. Results: Sixty-four breast cancer patients were included; none had marker-related complications. Following NAC, BCS could be easily performed in 60 patients guided by the silver markers, which were used as temporary implants and removed during surgery. Only 2 patients were seen with positive margins and were converted to mastectomy. Conclusion: Breast cancer localization using sterile silver markers before the initiation of NAC is safe, easy, inexpensive, and effective, causing no morbidity or significant pain to the patients.

Early and Late Functional Outcomes of Anal Sphincter-Sparing Procedures With Total Mesorectal Excision for Anorectal Adenocarcinoma

BACKGROUND: The study aims to assess the functional outcome of anal sphincter sparing procedures (SSP) with TME for anorectal adenocarcinoma. METHODS: In a multicentric, prospective, single-group study in the period between December 2012 and November 2017, 93 patients presented with anorectal adenocarcinoma were included in the study. Sixty-nine patients underwent SSP with TME. SSP included the combined approach of transabdominal TME with intersphincteric resection (ISR) or transanal transabdominal TME (TATA). Using the Per Anal Examination Scoring System (PASS), postoperative anal function was assessed after one year. RESULTS: Bowel motility time was 50 (±19) hours. The time needed for narcotic analgesia was 54 (±18.8) hours. Mean hospital stay was 15.4 (±10.25) days. Incidence of evident fecal incontinence after ISR is 10.6% (7/67 cases). The Per Anal Examination Scoring System (PASS) findings of 69 cases are as follows: extremely hypotonic 8.6% (6 cases), slightly hypotonic 26.1% (18 cases), normal tone 58% (40 cases), slightly stenotic 3 cases (4.3%), or occluded 2.9% (2 cases). Urinary dysfunction occurred in one case (1.4%). Temporary diversion was performed in 61 patients (87.1%). CONCLUSION: Sphincter preservation with TME for anorectal adenocarcinoma helps avoid permanent stoma and provides a reasonable functional outcome. PASS is a new application for postoperative assessment of anal function.

Non-specific colitis among patients with colitis: frequency and relation to inflammatory bowel disease, a prospective study / Colite inespecífica entre pacientes com colite: estudo prospectivo sobre sua frequência e relação com doença inflamatória intestinal

Abstract Background and study aim: The term non-specific colitis refers to an inflammatory condition of the colon that microscopically lacks the characteristic features of any specific form of colitis and is commonly seen in pathology reports of colonoscopy biopsies. In fact, it has been questioned whether it is a separate pathological entity or it is merely an intermediate stage in the course of inflammatory bowel disease. This study was conducted to estimate the prevalence of non-specific colitis among patients with colitis and characterize its natural history over a 6 months year period. Patients and methods: Eighty adult patients presented for colonoscopy were enrolled. In the final analysis they were divided into Group A; the non-specific colitis Group and Group B; the inflammatory bowel disease Group. All patients were subjected to: full history taking, full clinical examination, laboratory investigations: which included stool analysis, CRP, ESR, complete colonoscopy and entire random colon biopsies for histopathological examination. Results: Group A included 67 patients (83.75%) while Group B included 13 (16.25%) patients. Patients with IBD had clinical and laboratory features of inflammation significantly higher than patients with non-specific colitis. Six patients (8.95%) of non-specific colitis group developed histologic features of florid inflammatory bowel disease after 6 months. There were no independent predictors of this conversion. Conclusion: Among our 80 patients with colonoscopy and biopsy 67 (83.75%) were diagnosed as non-specific colitis and out of them 6 patients (8.95%) were reexamined after 6 months and proved to have inflammtory bowel disese this change was not linked to predictive factors.

Resumo Introdução e objetivos: O termo colite inespecífica (CI) refere-se a uma condição inflamatória do cólon que microscopicamente não apresenta características de qualquer forma específica de colite; é comumente observada em relatórios patológicos de biópsias de colonoscopia. De fato, tem-se questionado se esta seria uma entidade patológica separada ou apenas um estágio intermediário no curso da DII. Este estudo foi realizado para estimar a prevalência de CI entre pacientes com colite e caracterizar seu curso durante um período de seis meses. Pacientes e métodos: O estudo incluiu 80 pacientes adultos que se apresentaram para colonoscopia. Na análise, os pacientes foram divididos em dois grupos: grupo A (CI) e grupo B (DII) Todos os pacientes foram submetidos a anamnese completa, exame clínico completo e investigações laboratoriais que incluíram análise de fezes, PCR, VHS, colonoscopia completa e biópsias aleatórias de cólon para exame histopatológico. Resultados: Do total de pacientes, 67 foram alocados no grupo A (83,75%) e 13 (16,25%) no grupo B. Os pacientes com DII apresentavam sinais clínicos e laboratoriais de inflamação significativamente maiores do que o observado em pacientes com CI. Seis pacientes (8,95%) do grupo CI desenvolveram características histológicas de DII florida após seis meses. Não foram identificados preditores independentes para essa conversão. Conclusão: Entre os 80 pacientes submetidos a colonoscopia e biópsia, o diagnóstico de CI foi feito em 67 (83,75%); destes, seis pacientes (8,95%) foram reexaminados após seis meses e apresentaram DII, sendo que essa conversão não foi associada a fatores preditivos.

Resolved HBV behavior during the treatment of chronic HCV infection with direct-acting antivirals.

AIM: This paper aimed to assess and follow up the course of resolved HBV (hepatitis B virus) during and after treatment with direct-acting antiviral drugs (DAAs). BACKGROUND: Co-infection with hepatitis B and hepatitis C is increasingly recognized in patients with chronic hepatitis. Resolved HBV in patients with chronic HCV (hepatitis C virus) infection has been investigated during interferon therapy, and the investigators suggest a possible correlation with a lower response to anti-viral treatment, higher grades of liver histological changes, and development of hepatocellular carcinoma. METHODS: Three hundred and thirteen patients were included in our observational and prospective study; two hundred and fifty-three patients had chronic hepatitis C (CHC) (group I), and sixty patients had both CHC and resolved HBV-infection (group II). They all were eligible for treatment with DAAs therapy for chronic HCV in our hepatology unit, Internal Medicine Department, Zagazig University Hospitals from December 2017 to September 2018. They were subjected to thorough history taking, full clinical examination, routine laboratory investigations, HCV antibody, HCV RNA, HBV surface antigen (HBsAg), HBV surface antibody (anti-HBs) HBV core antibody (anti-HBc), and HBV-DNA quantitative levels. All patients were followed up at baseline, at the end of week 4 of anti-viral therapy, at the end of treatment and 12 weeks after treatment. RESULTS: Assessment at 28 days showed significant decreases in ALT and AST levels in both groups, with stabilization of these levels on follow-up at 12 and 24 weeks. The efficacy of treatment was comparable in both groups. No case of ALT flare was observed in either group. Similar outcomes regarding AST and ALT levels were found in patients with diseases associated with immune derangement. CONCLUSION: The risk of resolved HBV reactivation during or after treatment with DAAs is low.

Conscious sedation using propofol versus midazolam in cirrhotic patients during upper GI endoscopy: A comparative study.

AIM: We aimed to assess the safety and efficacy of propofol versus midazolam in cirrhotic patients undergoing upper GI endoscopy. METHODS: Ninety compensated cirrhotic patients (all met class I-III criteria according to the American Society of Anesthesia) were enrolled in this comparative study. They were classified into three groups according to scheduled pre-endoscopy sedation drugs; the midazolam group, which included 30 patients who received IV weight-dependent midazolam (0.05 mg/kg with additional doses of 1 mg every 2 min when necessary, up to a maximum dose of 0.1 mg/kg or 10 mg); the propofol group, which included 30 patients who received a propofol bolus dose according to age and weight (0.25 mg/kg with additional doses of 20-30 mg every 30-60 s when necessary, up to a maximum dose of 400 mg); and the combined group, which included 30 patients who received half a dose of midazolam and of propofol. RESULTS: Prolonged postendoscopy recovery times were reported in the midazolam group, while shorter recovery times were reported in the propofol and combined groups. All patients in the propofol and combined groups gained consciousness shortly postendoscopy; however, only half of the midazolam group's patients gained consciousness after the standard recovery time (10-30 min). Highly significant differences were found among the three groups regarding consciousness level according to the Glasgow coma scale, as well as regarding the occurrence of hypoxia during endoscopy. CONCLUSION: Considering safety and efficacy issues, propofol is better than midazolam in gastrointestinal endoscopy, especially in patients with liver cirrhosis.

Associated vitamin D deficiency is a risk factor for the complication of HCV-related liver cirrhosis including hepatic encephalopathy and spontaneous bacterial peritonitis.

The influence of vitamin D, 25-hydroxyvitamin D (25(OH)D), deficiency on hepatitis C virus (HCV)-related cirrhosis had been poorly elucidated especially in patients with hepatic encephalopathy (HE) and spontaneous bacterial peritonitis (SBP). We aimed to investigate the association between vitamin D deficiency and the risk of SBP or HE, including the mortality rate. Serum 25(OH)D levels were prospectively determined in 135 patients. Of them, 45 patients had complications with HE and 45 patients had complications with SBP; 45 cirrhotic patients without complication served as the control group. Vitamin D deficiency was defined as 25(OH)D levels < 20 ng/ml. Receiver operating characteristic (ROC) and Kaplan-Meier method with log-rank test were used in our statistical analysis. Predictors of survival were determined using Cox regression analysis. Serum 25(OH)D levels were significantly (P < 0.05) lower in the HE and SBP groups than in the control group (6.81 ± 2.75, 7.15 ± 2.10, 16.28 ± 6.60, respectively). Moreover, serum 25(OH)D levels were significantly lower in the high HE grade than in the low grade (P < 0.001). Regarding the SBP group, classic SBP was associated with lower 25(OH)D levels compared to other types (P < 0.001). ROC curve revealed that lower 25(OH)D levels less than 7.1 ng/ml and 6.6 ng/ml could predict the mortality in SBP and HE patients, respectively, with high sensitivity and specificity. Serum 25(OH)D levels < 5 ng/ml were associated with significant higher mortality rate (HR = 2.76, P = 0.001). Lower 25(OH)D levels were associated with HE and SBP in cirrhotic patients. In addition, it may be considered a prognostic parameter for the severity of liver cirrhosis.

Prevalence of occult hepatitis C virus infection in patients who achieved sustained virologic response to direct-acting antiviral agents.

The reappearance of HCV infection months or years after sustained virologic response (SVR) may be due to the persistence of HCV in tissue cells in spite of being undetected in serum. This situation is known as occult hepatitis C infection (OCI). We aimed to assess the prevalence of OCI in Egyptian patients with chronic hepatitis C (CHC) who achieved SVR after treatment with direct-acting antiviral agents (DAA). We carried out a cross-sectional study at the Advanced Center for Liver Diseases of Zagazig University Hospitals and Al-Ahrar Viral Hepatitis Treatment Center, Sharkia Governorate, Egypt. One hundred and fifty adult patients with CHC, who achieved SVR 12-24 weeks after end of treatment with sofosbuvir/daclatasvir ± ribavirin (139 patients, 92.67%), sofosbuvir/ledipasvir ± ribavirin (eight patients, 5.33%), sofosbuvir/simeprevir (two patients, 1.33%), and ombitasvir/ paritaprevir/ritonavir + ribavirin (one patient, 0.67%), according to the Egyptian National Committee for Control of Viral Hepatitis, were included in the study. We tested these patients for HCV RNA in peripheral blood mononuclear cells (PBMCs) immediately after confirmation of SVR12-24 weeks. Statistical analysis was performed by means of the Shapiro-Wilk test, Mann-Whitney U test, Chi-square test, and Fisher's exact test. Seventeen patients (11.33%) were positive for PBMNCs HCV RNA. The prevalence of OCI was highest in patients treated with simeprevir/sofosbuvir (2/2 patients). There is a substantially high prevalence of OCI after treatment with DAAs. We recommend dual testing for HCV RNA in both serum and PBMCs at the end of treatment of HCV infection with DAAs and during validation of the SVR following the initial response.

Parotid Quadrantectomy Is a Safe Management for Localized Pleomorphic Adenoma.

AIM: Pleomorphic adenoma is the most common benign tumor of the parotid gland and is classically treated with superficial or total parotidectomy. Less radical surgeries have been proposed to minimize the risk of facial nerve injury. The oncological safety of these procedures remains controversial. We conducted this study to evaluate the safety of superficial hemi-lobectomy (quadrantectomy). PATIENTS AND METHODS: Retrospective analysis was conducted on the paraffin sections of archived superficial parotidectomy specimens from 11 male and 6 female patients (median age 33 years). The microscopic extent of extra-capsular extension was determined on pathological revision. In addition, prospective evaluation of 12 quadrantectomy procedures (M/F = 7/5, median age = 36 years) compared to 24 radical surgeries (M = F, median age = 40 years) regarding temporary and persistent facial nerve dysfunction on routine clinical assessment and recurrence rate. RESULTS: On retrospective pathological revision, pleomorphic adenomata had a median microscopic spread of 3 mm beyond capsule in paraffin sections (SD = 3.6). On prospective analysis with a median follow-up of 33 months (range = 18-54 months), quadrantectomy had similar relative risk of temporary facial nerve dysfunction evaluated at the immediate postoperative period as well as persistent nerve dysfunction assessed at 3 months (P = 0.701 and P = 0.902, respectively). Of the whole study population, one case of recurrence after total parotidectomy was observed at mid-term follow-up (P = 1.000). CONCLUSION: Parotid quadrantectomy is a safe management for smaller pleomorphic adenomata localized close to one of the two divisions of the facial nerve.

Role of Hepatic Resection for HCC in the era of Transplantation; an Experience of Two Tertiary Egyptian Centers.

The surgical treatments of hepatocellular carcinoma (HCC) in a cirrhotic liver include both hepatic resection and liver transplant. While the liver transplant is considered as a golden therapy, it has some obstacles including shortage of organs especially living donors, economic circumstances, and the progression of a tumor while waiting for the transplant so the second choice which is resection should have a role. In this study, 84 patients with HCC (who were legible for transplant according to Milan and extended selection criteria) were enrolled for hepatic resection. The outcome including complication and the oncologic outcome was evaluated. We followed our patients for 15 months as a median follow-up (range from 3 to 50 months); we noticed 10 tumor relapse (11.7%) and seven lost (8.3%). We also noticed no recurrence. Patients' overall survival showed a median of 15 and 50 months, respectively. We can conclude that there is reasonability for HR as an effective optional treatment for patients with HCC who are legible for transplant particularly for patients with a Child-A scoring.

Lateral Versus Anterior Approach Laparoscopic Splenectomy: A Randomized-controlled Study.

PURPOSE OF THE STUDY: The study compares prospectively the hospital stay and postoperative complications of anterior (ALS) versus lateral (LLS) approach for laparoscopic splenectomy. MATERIALS AND METHODS: Between September 2011 and April 2015, 94 patients with splenomegaly were referred to the surgical unit in the Oncology Center of Mansoura University, Egypt. Only 80 patients with splenomegaly <30 cm underwent an open-label randomized allocation into 2 equal parallel groups. Indications were hematological in 52 patients (65%) and malignant splenic conditions in 28 patients (35%). Two patients younger than 18 years, 4 patients with splenomegaly >30 cm, and 8 patients with associated surgical comorbidities were excluded. Three days' hospital stay reduction with LLS was suggested with a power of 80% and P-value of 0.05. RESULTS: The mean hospital stay was significantly shorter (P=0.001) after LLS. Laparoscopic splenectomy was completed in 68 patients (85%). Twelve patients (15%) required open splenectomy with no difference between groups. The operation time was significantly shorter in LLS (P=0.013). Blood loss (P=0.057) and blood transfusion (P=0.376) showed no difference between the two groups. The times until resumption of oral intake (P=0.019) and drain removal (P=0.011) were statistically shorter in LLS. CONCLUSIONS: LLS is more safe and feasible with shorter hospital stay compared with ALS.

The outcome of oncoplastic techniques in defect reconstruction after resection of central breast tumors.

BACKGROUND: Traditionally, conservative breast surgery was contraindicated in centrally located breast tumors, with total mastectomy as the treatment of choice. However, restorations of the central defects by the oncoplastic volume displacement or replacement techniques have been shown to be effective. The aim of the current study was to assess the surgical outcome of oncoplastic techniques after central breast tumors resection. METHODS: Thirty patients with central breast cancer, including two patients with Paget disease, treated at the Oncology Center of Mansoura University (Egypt) between June 2011 and December 2014 were included in this study. The oncoplastic techniques performed were Grisotti advancement rotational flap in eight (26.7%) patients, classic skin-sparing mastectomy (SSM) with latissimus dorsi pedicled flap in 20 (66.7%) patients, and skin-reducing mastectomy (SRM) with latissimus dorsi pedicled flap using wise pattern inverted T incision in two (6.7%) patients. The choice of the oncoplastic techniques depends on the achievement of free safety margins, the breast volume, and its ptotic degree. RESULTS: The median age was 40.5 years (range; 23-55). There were no major complications that require repeating the oncoplastic techniques. Recorded complications included wound dehiscence (4/30, 13.3%) donor site seroma (4/30, 13.3%), and surgical site infection (1/30, 3.3%). The 6-month subjective patient satisfaction was excellent in 21 (70%) patients, good in 6 (20%) patients, and fair in 3 (10%) patients. There was no episode of local recurrence or systemic metastasis after an average follow-up duration of 24 months (range; 6-42). CONCLUSIONS: Restoring the central defect after resection of the central breast tumors can be safely achieved using oncoplastic procedures including the Grisotti technique or the design of SSM or SRM with immediate breast reconstruction. In our patients, these procedures yield a satisfactory esthetic outcome with lower morbidity.

Genetic polymorphism of IL-23R influences susceptibility to HCV-related hepatocellular carcinoma.

BACKGROUND: Genetic variations may play an important role in the development of HCC in HCV patients. Variants of IL23R gene were investigated for association with many diseases like chronic inflammatory disorders, RA, inflammatory bowel diseases and the susceptibility to the development of gastric cancer but no data are available concerning the association of IL23R gene (rs11209026) polymorphism with HCC development in HCV patients. Therefore the current study aimed to analyze this polymorphism within the gene to evaluate its contribution to chronic HCV susceptibility and/or HCC development in Egyptian patients. SUBJECTS AND METHODS: One hundred and ninety-two patients with chronic HCV infection were included in this study (92 of them without HCC and 100 of them with HCC). One hundred healthy control subjects with no history of previous liver disease (HBV and HCV infection were negative) were included in the study. The IL23R polymorphism (rs11209026 G>A) were genotyped by real time PCR. RESULTS: We found a significant lower incidence of GA and AA genotype in HCV patients with HCC compared to those without HCC (p=0.026 and 0.040 respectively) and compared to control group (p=0.008 and 0.007 respectively). While, no significant difference between control and HCV patients without HCC groups was found. CONCLUSIONS: Our study suggests that wild type IL-23R GG serves as a risk factor for HCC and supports for the protective role of the rare variant rs11209026 (Arg381Gln) against HCV-related HCC in Egyptian patients.

Electrochemical reduction of N,N'-thiobisphthalimide and N,N'-dithiobisphthalimide: ejection of diatomic sulfur through an autocatalytic mechanism.

The electrochemical reduction of N,N'-dithiobisphthalimide and N,N'-thiobisphthalimide is investigated using electrochemical techniques and theoretical calculations. The results are rationalized using adequate electron transfer theories. The reduction leads to the ejection of diatomic sulfur and involves an interesting autocatalytic mechanism. This mechanism is dependent on the concentration of the initial compound and the cyclic voltammetric scan rate. The starting material is reduced both at the electrode and through homogeneous electron transfer from the produced sulfur. The initial electron transfer follows a stepwise mechanism involving the formation of the corresponding radical anion. This is supported by both the electrochemical data and the theoretical calculation results. The radical anion of the N,N'-dithiobisphthalimide dissociates through cleavage of the N-S chemical bond and not the S-S chemical bond. Application of the extension of the dissociative electron transfer theory to the dissociation of radical anions shows that the N-S chemical bond dissociates despite being stronger than the S-S chemical bond. This is due to the large difference in the oxidation potentials of the two potential anions (the phthalimidyl anion and the phthalimidyl thiyl anion). The electrochemical reduction of N,N'-thiobisphthalimide involves the intermediate formation of N,N'-dithiobisphthalimide and hence the autocatalytic process is less efficient.

Urinary biomarkers of acute kidney injury in patients with liver cirrhosis.

Acute kidney injury (AKI) is a common complication in cirrhotic patients. Serum creatinine is a poor biomarker for detection of renal impairment in cirrhotic patients. This study aimed to evaluate urinary neutrophil gelatinase-associated lipocalin (NGAL) and urinary interleukin-18 (IL-18) as early biomarkers of acute kidney injury in cirrhotic patients. 160 patients with cirrhosis admitted to the Liver Units at Zagazig University Hospitals were classified into three groups: (I) nonascitic patients, (II) ascitic patients without renal impairment, and (III) ascitic patients with renal impairment. Patients with renal impairment were further divided into four subgroups: [A] prerenal azotemia, [B] chronic kidney disease (CKD), [C] hepatorenal syndrome (HRS), and [D] acute tubular necrosis (ATN). Significant elevation of both urinary NGAL and urinary IL-18 in cirrhotic patients with renal impairment especially in patients with ATN was observed. Urinary NGAL and urinary IL-18 have the ability to differentiate between AKI types in patients with cirrhosis. This could improve risk stratification for patients admitted to the hospital with cirrhosis, perhaps leading to early ICU admission, transplant evaluation, and prompt initiation of HRS therapy and early management of AKI.

Synthesis and antibacterial activity of novel curcumin derivatives containing heterocyclic moiety.

A series of curcumin derivatives containing heterocyclic moiety have been synthesized and evaluated for their antibacterial activities. The chemical structures of the synthesized compounds were verified on the basis of spectral data and elemental analyses. Investigation of antimicrobial activity of the derivatives demonstrated the ability to inhibit Gram-positive microorganisms with zone of inhibition ranging from 14-18 mm, MIC ranging between 0.0625 and 0.25 mg/mL. Among all tested derivatives, diazepine 4 exhibited remarkable potency against Gram-positive bacteria S. aureus. An extensive study is underway to optimize the effectiveness of diazepine type of compounds and to determine their mode of action.

The intriguing reaction of aromatic sulfonyl phthalimides with gold surfaces.

We report on a series of arene sulfonyl phthalimides which were prepared and used to modify polycrystalline gold and Au(111) gold surfaces. Three investigated compounds are the p-iodo-, the p-methoxy-, and the p-fluoro-benzenesulfonyl phthalimides. X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and scanning tunneling microscopy (STM) studies were used to characterize the modified surfaces. The XPS data show that all three investigated compounds decompose on gold surfaces. The decomposition leads to the adsorption of sulfur and ejection of the other groups except for the p-iodo compound, which also leads to the deposition of iodine. The cyclic voltammetry data confirm these results and show that high coverage values of deposited sulfur are obtained. High-resolution STM imaging showed a dynamic behaviour of sulfur on gold for all compounds. Movement of sulfur species on the Au(111) surface is observed. Various phases including a new 'zig-zag' pattern and a new 2 : 1 line pattern are presented. Sequential STM imaging also showed movement of one area of sulfur while another remains static. These results are important because (i) they provide direct experimental evidence that these hexavalent sulfur compounds react with gold surfaces breaking all sulfur chemical bonds, (ii) they show that sulfonyl phthalimides can be used as efficient precursors for the deposition of sulfur on gold, and (iii) very importantly they show the adlayer nature of the sulfur modified gold surface which has been a heavily debated question.

Dissociation of aryl sulfonyl phthalimide radical anions: relevance to the biological activity of aryl sulfonyl amides.

The reduction of two aryl sulfonyl phthalimides leads to the corresponding radical anions. Surprisingly, that of the nitro-derivative decomposes faster than that of the methyl derivative. A theoretical investigation along with application of the dissociative ET theory to the decomposition of radical anions allows rationalization of this unexpected behavior.

New insights into sulfur deposition on gold using dithiobisphthalimide as a new precursor.

Dithiobisphthalimide is used as a new precursor for the spontaneous deposition of sulfur on gold surfaces in acetonitrile. Characterization of the modified surfaces is achieved using X-ray photoelectron spectroscopy (XPS), electrochemistry and scanning tunneling microscopy (STM). The reported results indicate that the sulfur deposition is an efficient and fast process and that high coverages can be reached very quickly. Sequential high-resolution STM in air allows the direct observation, for the first time, of the mobility of the usually observed rectangular structures as individual units. It also shows the reversible association/dissociation of these rectangles. The nature of these structures is highly debated in the literature and the present work provides new insights into their nature through the use of a new sulfur precursor under non-traditional conditions. To explain our results we consider these structures as simple sulfur adlayers on the gold surface.

Application of the dissociative electron transfer theory and its extension to the case of in-cage interactions in the electrochemical reduction of arene sulfonyl chlorides.

Important aspects of the electrochemical reduction of a series of substituted arene sulfonyl chlorides are investigated. An interesting autocatalytic mechanism is encountered where the starting material is reduced both at the electrode and through homogeneous electron transfer from the resulting sulfinate anion. This is due to the homogenous electron transfer from the two-electron reduction produced anion (arene sulfinate) to the parent arene sulfonyl chloride. As a result, the reduction process and hence the generated final products depend on both the concentration of the substrate and the scan rate. A change is also observed in the reductive cleavage mechanism as a function of the substituent on the phenyl ring of the arene sulfonyl chloride. With 4-cyano and 4-nitrophenyl sulfonyl chlorides a "sticky" dissociative ET mechanism takes place where a concerted ET mechanism leads to the formation of a radical/anion cluster before decomposition. With other substituents (MeO, Me, H, Cl, and F) a "classical" dissociative ET is followed, where the ET and bond cleavage are simultaneous. The dissociative electron transfer theory, as well as its extension to the case of strong in-cage interactions between the produced fragments, along with gas phase chemical quantum calculations results helped us to rationalize both the observed change in the ET mechanism and the occurrence of the "sticky" dissociative ET mechanism. The radical/anion pair interactions have been determined both in solution as well as in the gas phase. The study also shows that despite the low magnitude of in-cage interactions in acetonitrile compared to the gas phase their existence strongly affects the dynamics of the involved reactions. It also shows that, as expected, these interactions are reinforced by the existence of strong electron-withdrawing substituents. The occurrence of an autocatalytic process and the existence of the radical/anion interaction may explain the differences previously observed in the reduction of these compounds in different media.