Unique report of iliocaval endovascular reconstruction successfully enabling a kidney transplant.

Patients with end-stage renal disease and iliocaval venous obstruction are normally nonviable recipients of kidney transplantation. We report a case of a 34-year-old male patient who has been receiving hemodialysis as renal replacement therapy for 6 years due to immunoglobulin A nephropathy. Past medical history included multiple central venous catheter infections and catheter-associated thrombosis. Iliac confluence and inferior vena cava occlusion previously excluded the patient from the renal transplantation list. The exhaustion of venous access sites was already documented. After multidisciplinary discussion, the patient was proposed for endovascular iliocaval reconstruction aiming for a future kidney transplant. Iliocaval recanalization was achieved through bilateral femoral access. Inferior vena cava and iliac angioplasty were performed. A dedicated venous stent was deployed in the inferior vena cava, followed by a double-barrel reconstruction of the iliac confluence. Successful iliocaval recanalization was accomplished. Five months after kidney transplantation was performed with a deceased donor graft in the right iliac fossa. The postoperative period was uneventful. After 12 months, the patient remained free from kidney replacement therapies with a serum creatinine level of 1.3 mg/dL. To the best of our knowledge, this is the first clinical description of a successful kidney transplant in a patient with a previous iliocaval reconstruction.

Use of a Paclitaxel Drug-Eluting Stent for the Treatment of Hemodialysis Access Outflow Stenosis.

PURPOSE: To evaluate the outcomes and durability of drug-eluting stents (DESs) for the treatment of hemodialysis access outflow stenosis. MATERIAL AND METHODS: A single-center retrospective analysis was conducted of all patients with hemodialysis vascular access outflow stenosis treated with a paclitaxel-coated DES (Eluvia; Boston Scientific, Marlborough, Massachusetts) between January 2020 and July 2022. A total of 34 DESs were implanted to treat outflow stenosis in 32 patients. Primary target lesion patency after stent deployment was the main outcome. Comparison between the time interval free from target lesion reintervention (TLR) after previous plain balloon angioplasty (PBA) and that after stent deployment for the same target lesion was considered a secondary outcome. RESULTS: The primary patency at 6, 12, and 18 months was 63.1%, 47.6%, and 41.7%, respectively. The secondary patency rate was 100% at 18 months. The median time interval free from TLR increased from 4.1 to 11.9 months (P < .001). No adverse events were observed during the median follow-up period of 387 days. CONCLUSIONS: The patency rates after use of DES for hemodialysis access outflow stenosis were comparable with results for drug-coated balloons and stent grafts, addressing recoil and minimizing the risk of jailing by a covered stent.

Outflow Rescue of Elbow-Blockade Forearm Arteriovenous Fistulas: Outcomes of Open Surgical Techniques.

BACKGROUND: Venous scarring at the elbow is a common problem that can cause early and late forearm arteriovenous fistula (AVF) dysfunction in hemodialysis patients. However, any effort to prolong the long-term patency of distal vascular accesses could benefit the patient's survival, maximizing the use of restricted venous patrimony. This study aims to report a single-center experience in the recovery of distal autologous AVF with venous outflow obstruction at the elbow using different surgical techniques. METHODS: Retrospective observational study of all patients treated at a single vascular access center from January 2011 to March 2022, with dysfunctional forearm AVFs presenting with outflow stenosis or occlusions at the elbow treated by open surgery, using 3 different surgical techniques. Demographics and clinically relevant data were collected. Evaluated endpoints included primary, assisted primary, and secondary patency rates at 1 and 2 years. RESULTS: Twenty-three patients with elbow-blocked outflow forearm AVFs have been treated with a mean age of 64 ± 15 years. The majority (96%) had a radiocephalic fistula. The median time from vascular access creation to intervention was 34.5 months (12-216 months). A total of 24 procedures have been performed using 3 different surgical techniques for bypassing the obstructed venous outflow at the elbow. Technical success was achieved in 96% of the surgically treated patients. Primary and secondary patency rates at 1 year were 67.4% and 89.4%, respectively, and 52.9% and 82.0% at 2 years, with a median follow-up of 19 months (6-92 months). CONCLUSIONS: AVFs outflow stenosis or occlusions at the elbow not amenable to endovascular therapy could lead to vascular access abandonment. Our study demonstrates multiple surgical solutions to avoid this adverse outcome. Elbow venous outflow surgical reconstruction seems effective for distal vascular access preservation. Close surveillance is essential for timely endovascular treatment of newly developed stenosis at the venous drainage.

Comparison between Surgical Techniques Used for Revision of the Filter Bleb: A Randomized Controlled Clinical Trial.

INTRODUCTION/PURPOSE: The aim of this study was to compare two surgical revision techniques in failed trabeculectomies after 6 months. METHODS: Patients diagnosed with open-angle glaucoma who underwent trabeculectomy in at least one eye with uncontrolled intraocular pressure (IOP) after trabeculectomy performed at least 6 months before were enrolled in this prospective trial. All participants underwent a complete ophthalmological examination at baseline. Randomization was performed to one eye per patient to double-masked trabeculectomy revision or needling. Patients were examined on the first day, 7 days, 14 days, and then monthly until completing 1 year after surgical intervention. All follow-up visits included the following: patients reported ocular and systemic events, best-corrected visual acuity, IOP, slit-lamp examination, and optic disc evaluation for cup-to-disc ratio. Gonioscopy and stereoscopic optic disc photographs were taken at baseline and 12 months. After 1-year, the IOP and number of medications were compared between the groups. Absolute success criteria in the study were IOP <16 mm Hg, for 2 consecutive measurements without using a hypotensive medication. RESULTS: Forty patients were included in this study. Among them, 38 completed 1-year follow-up (18 in revision group and 20 in needling group). The age ranged from 21 to 86 years, with a mean of 66.82 ± 13.44. At baseline, the average IOP was 21.64 ± 5.12 mm Hg (range from 14 to 38 mm Hg) in the entire group. All patients were using at least two classes of hypotensive eye drops, and 3 patients were using oral acetazolamide. The mean use of hypotensive eye drop medications was 3.11 ± 0.67 at the baseline for the entire group. In the present study, 58% of the patients presented complete success, 18% qualified success, and 24% failed in both groups. After 1-year treatment, both techniques were similar for IOP parameters and also for number of medications (p = 0.834 and p = 0.433, respectively). Regarding intra- or postoperative complications, one patient in each group needed a new surgical intervention, one in the needling group due to shallow anterior chamber and one in the revision group due to spontaneous Seidel sign, and one patient in the needling group underwent posterior revision due to fail. CONCLUSIONS: Both techniques were safe and effective for IOP control after 1 year of follow-up in patients who underwent to trabeculectomy more than 6 months before.

Ruptured arteriovenous fistula pseudoaneurysm treatment by balloon-assisted direct percutaneous thrombin injection.

We present the case of a male patient on hemodialysis with a ruptured pseudoaneurysm in a brachiocephalic arteriovenous fistula (AVF) and with edema and pain in the right arm attended to in the emergency department. An ultrasonographic scan identified a ruptured pseudoaneurysm with hemorrhagic infiltration of the arm muscular tissues. We performed a percutaneous ultrasound-guided thrombin injection with an angioplasty balloon inflated in the lumen of the AVF achieving the pseudoaneurysm thrombosis. After 6 months of follow-up, the patient's arteriovenous access remains functional. Percutaneous ultrasound-guided thrombin injection assisted by an angioplasty balloon may be a good alternative to surgical intervention in the treatment of symptomatic growing pseudoaneurysms of the arteriovenous fistula with the benefit of preserving the vascular access.

Emergency Repair of a Ruptured Para-Renal Abdominal Aortic Aneurysm in a Patient with a Functional Renal Graft: A Case Report and Review of the Literature.

INDRODUCTION: Rupture of and abdominal aortic aneurysm (AAA) in a kidney transplant patient is a rare and rarely reported event. Emergent treatment can be challenging and should achieve effective aortic repair while minimizing ischemic damage to the renal graft during aortic cross-clamping. Several renal protective measures have been proposed such as permanent or temporary shunts, renal cold perfusion and general hypothermia. CASE REPORT: We report the effective treatment of a para-renal AAA in a patient with a functional renal allograft. A temporary extra-corporeal axillofemoral shunt was constructed to maintain graft's perfusion during open surgical repair. EVAR was not an option due to a short aortic neck. The postoperative period was complicated by colon ischemia and aortic graft infection. At 3 years follow-up the patient was well and graft's function was unchanged. CONCLUSION: This case is a reminder that renal graft protection must be accounted for when AAA rupture occurs in kidney transplant patients. We reviewed the literature to find previously reported cases and how they were managed.

Characteristics of the Filtering Bleb and the Agreement between Glaucoma Specialist and Anterior Segment-Optical Coherence Tomography Assessment.

INTRODUCTION: This study aimed to evaluate the characteristics of the filtering bleb in failed late trabeculectomy and the agreement between glaucoma specialist assessment and anterior segment-optical coherence tomography (AS-OCT) system assessment in terms of the presence of subconjunctival fluid in the filtering bleb. METHODS: Patients with a diagnosis of glaucoma who were scheduled to undergo trabeculectomy in at least one eye and with uncontrolled intraocular pressure (IOP) were enrolled. All participants underwent a complete ophthalmological examination. The presence of fluid under the filtering bleb was first evaluated by a glaucoma specialist using biomicroscopy evaluation and then using the OCT 1000 AS-OCT Version 3.0.1.8 (Carl Zeiss Meditec, Dublin, CA, USA) system. A Kappa statistical test was used to evaluate the agreement between AS-OCT and the examiner. The correlation between conjunctiva and tenon thickness and clinical parameters was also assessed. RESULTS: Forty eyes of 40 patients were evaluated in this study. The ages ranged from 21 to 86 years, with a mean of 66.55 ± 12.33. The average IOP was 21.20 ± 4.44 mm Hg (range 14-38 mm Hg) in the entire group. The mean thickness of the conjunctiva and tenon was 302.03 ± 406.76 µm (range 251-1,616 µm). There was a significant negative correlation between the mean thickness of the conjunctiva and tenon and IOP (p = 0.045; confidence interval = -0.558, 0.024). Additionally, there was a significant negative correlation between the mean thickness of the conjunctiva and tenon, and the number of medications used at baseline (p = 0.043; confidence interval = -0.538, 0.051). There was significant negative correlation between the horizontal measurement of the bleb and the use of glaucoma medications (p = 0.017; confidence interval = -0.560, 0.004). A total of 26 patients were determined to have fluid by the examiner (glaucoma expert), and the presence of fluid in AS was confirmed in 19 patients by AS-OCT. Of the 14 patients who were determined to have an absence of fluid, this was confirmed by AS-OCT in 7 patients (Kappa = 0.231; agreement of 65.00%). CONCLUSION: There is fair agreement between glaucoma specialist assessment and AS-OCT assessment in terms of the presence of fluid in trabeculectomy. Our findings highlight the importance of AS-OCT in some patients before deciding upon a new intervention.

Facial Reconstruction Based on Combined Three-Dimensional Printing and Microsurgical Free Transfer.

There are patients with craniofacial deformity that can lead to extensive bone loss and severe disfigurement. Autologous reconstruction may be challenging in these patients, and it is usually associated with flap donor area morbidity and unfavorable aesthetic and functional results. A 51-year-old patient with human immunodeficiency virus infection, developed in the context of immunosuppression a fulminant fungal rhino-sinusitis with the need for surgical debridement, and in consequence extensive destruction of the nasal cavity and upper jaw, resulting in severe disfigurement due to nasal deformity and maxillary collapse. Human immunodeficiency virus disease was controlled and the complex craniofacial defect was posteriorly reconstructed with direct 3-dimensional (3D) printing combined with microsurgical free tissue transfer. The 3D facial implant, in titanium, was individualized and fabricated based on computed tomography images of the patient. A radial forearm free flap was used since a soft-tissue defect was anticipated after scar release and implant placement. It allowed simultaneous coverage of the palate, the anterior surface of maxilla and intranasal lining. The flap survived despite flap venous congestion in the postoperative period probably facilitated because of the complex 3D flap configuration and pedicle tunneling into the neck. After 9 months, the patient showed a tremendous aesthetic and functional improvement. The 3D printing was useful in our patient with craniofacial reconstruction. Its combination with free tissue transfer may improve the surgeon's armamentarium when dealing with complex patients.

Surgical Treatment of Cephalic Arch Stenosis through Rotation of the External Jugular Vein.

The percutaneous transluminal balloon angioplasty or cephalic vein transposition is the treatment for cephalic arch stenosis. In some cases, rotation of the external jugular vein may be a good option for the cephalic arch problems. We describe a new technique to treat cephalic arch stenosis. The technique enables the cephalic arch and subclavian vein to be bypassed altogether through the rotation of the external jugular vein. It consists of 3 small incisions, thus causing minimal surgical damage.

Templated Growth of Pd Nanoparticles Using Sputtering Deposition Process and Its Catalytic Activities.

A simple method based on sputtering deposition of Pd onto mesoporous SiO2 (SBA-15) was employed to produce supported Pd nanoparticles (NPs) that can be used as hydrogenation catalysts. The use of sputtering deposition eliminates contaminants and avoids additional drawbacks of traditional chemical methods applied to prepare heterogeneous supported metal catalysts. A mechanical resonant stirrer was used to revolve the SBA-15 powder and ensure homogeneous distribution of the Pd NPs over the support. The SBA-15 pores act as templates for Pd NPs and drive nanostructure growth. Consequently, the NPs obtained have the same diameter as that of the SBA-15 channels (~5 nm) and elongated particles are formed as sputtering deposition increases. The SBA-15 supported Pd NPs (Pd NPs/SBA-15) were tested in a probe hydrogenation of cyclohexene reaction to evaluate the catalytic activity of the Pd NPs. Turnover frequency (TOF) of 2000 min-1 were achieved with the lower Pd NPs concentration (0.15 wt%) catalyst.

The Role of Doppler Ultrassonography in Significant and Borderline Stenosis Definition.

BACKGROUND: The definition of significant stenosis (SS) remains controversial. METHODS: We retrospectively reviewed 1,040 consultations. SS was defined in the presence of clinical and echo-Doppler (DDU) criteria: Qa <500 mL/min or Qa decrease >25%; RI >0.7 in the feeding artery or absolute minimal luminal stenosis diameter <2.0 mm. Stenosis without any additional criteria were considered borderline stenosis (BS). RESULTS: Two hundred twenty-one arteriovenous fistulas (AVFs) were included: 58.8% had SS, 18.6% had BS, and 22.6% had no dysfunctional access (ND). SS had a significantly higher thrombotic events than BS and ND (13.1 vs. 4.4%, p = 0.018). The annual thrombosis rate was 0.007, 0.037, and 0.004 in the ND, SS, and BS, respectively. AVF cumulative survival at 5 years was significantly lower in SS (89.5%) compared to BS (100%) and ND (97.4%; p = 0.03). BS had an HR for AVF failure of 1.1, p = 0.955, while the SS presented an HR of 5.9, p = 0.09. CONCLUSION: AVF clinical monitoring with additional DDU criteria appear to be appropriate for therapeutic referral.

Pharyngocutaneous and tracheoesophageal fistula closure using supraclavicular artery island flap.

BACKGROUND: Pharyngocutaneous fistula is a common complication of laryngopharyngeal surgery, being associated with increased morbidity and mortality. Classical regional and free flaps, frequently used in the treatment of this complication, have several limitations, including bulking, donor site morbidity and long operative time. The supraclavicular artery island flap (SCAIF) is a fasciocutaneous flap and presents as an alternative option with good results and without the previously stated limitations. We describe our experience with SCAIF in pharyngocutaneous and tracheoesophageal fistula closure. METHODS: Between April and December 2017, four patients with pharyngocutaneous and two patients with tracheoesophageal fistula underwent fistula closure with SCAIF. Clinical records were retrospectively reviewed. RESULTS: Pharyngocutaneous fistulae were associated with anterior esophageal wall defects ranging from 4 to 13.5 cm2. Tracheoesophageal fistulae defects were smaller (approximately 2 cm2). Fistula closure was achieved in all patients, oral diet was started on the 14th day post-operative and there were no signs of recurrence during follow-up. The donor area was complicated with the formation of hematoma in two patients. CONCLUSIONS: The SCAIF has unique features that makes it an ideal option for pharyngocutaneous and tracheoesophageal fistula closure, namely, reliable perfusion, quick and simple dissection, pliability and minor donor site morbidity. Local complications do not significantly affect long term morbidity of the donor area and can be avoided with simple measures.

The facial artery perforator flap for intraoral reconstruction of a mouth floor defect.

Facial artery perforator flaps have been recently reported by different authors for perioral, nasal alar and cheek defects, but not for intraoral reconstruction. We have extended the use of the facial artery perforator flap in a 56-year-old man with a squamous cell carcinoma of left mouth floor, who was submitted to tumor resection with marginal mandibulectomy and left supraomohyoid neck dissection. The flap was designed according to the size of the defect (5 × 3 cm), centered on the perforator to create a symmetric flap and was tunnelled intraorally by means of a 90° rotation. The postoperative period was uneventful, allowing timely initiation of adjuvant radiotherapy. After 8 months, there were no signs of local recurrence or wound dehiscence, and functional outcomes were satisfactory. The main advantages of this flap in this case were the reduction in morbidity at the donor site with preservation of nerves, muscles and facial artery, and it allowed greater freedom. To the best of the authors' knowledge, this technique has not been reported before. It may constitute an important reconstructive option when dealing with similar defects, if our results are confirmed in larger series.

Brachio-Brachial Arteriovenous Fistula Superficialization with Short Skip Incisions.

The exhaustion of superficial venous patrimony or reduced diameter of superficial veins usually prevents patients from having an arteriovenous fistula created. In such cases, using deep vessels can be a more viable option as opposed to an arteriovenous graft. We describe a new approach for the brachio-brachial arteriovenous fistula creation technique. It consists of 3 small incisions, thus causing minimal surgical damage. We have found it to be better tolerated by the patients and well received by dialysis nurses. This procedure also allows improved access for cannulation and more available puncture sites.

Management of Pharyngocutaneous Fistula With Negative-Pressure Wound Therapy.

BACKGROUND: Pharyngocutaneous fistula is a common complication of laryngopharyngeal surgery and is associated with increased morbidity and mortality. Beyond the classical management, negative-pressure wound therapy (NPWT) can be an alternative and effective treatment. CLINICAL REPORT: Two patients with pT3N0M0 squamous cell carcinoma of pyriform sinus were subjected to total laryngectomy and pharyngoesophageal reconstruction of a circular (patient 1) and an anterior wall defect (patient 2) with radial forearm free flap and pectoralis major muscle flap, respectively. Both developed a pharyngocutaneous fistula and NPWT was used.A significant decrease of the fistula aperture and exudate was observed after 22 and 21 days of NPWT in patients 1 and 2, respectively. After that standard wound care was instituted and closure of the fistulae was accomplished in 5 and 7 days, respectively. CONCLUSION: Negative-pressure wound therapy can be an effective treatment for pharyngocutaneous fistula closure, either in the setting of fistulae that persist besides multiple surgical revisions using muscle flaps or as a first-line therapy when fistulae develops.

The Keystone Perforator Island Flap and its Use in Complex Defects of the Trunk: a Case Report.

Complex defects of the trunk present a reconstructive challenge and conservative treatment is frequently unsuccessful. Perforator flaps have become a common option for this problem. The keystone perforator island flap (KPIF) is a fasciocutaneous advancement flap, based on randomly located perforators vessels, whose dissection and exposure is not required. Designed in a curvilinear trapezoidal shape, it allows primary closure of large defects, while avoiding secondary defects and minimizing the need for more complex pedicled flaps or microsurgical reconstructive techniques. The clinical case of a 52-year-old male with stable coronary artery disease and severe aortic stenosis, with severe left ventricular dysfunction, who underwent coronary artery bypass graft surgery and aortic valve replacement is presented. During the post-operative period, he developed anterior mediastinitis and presented a large median sternotomy wound dehiscence, refractory to medical treatment and surgical debridement. The patient underwent reconstruction of the defect with a bilateral KPIF and application of VAC therapy, with favorable outcome. The KPIF is an useful and reliable reconstruction technique for complex defects, that has shown shorter operative times, lower risk of total flap necrosis, reduced donor-site morbidity and favorable aesthetic results, making it a good option in patients with multiple comorbidities.

Os defeitos complexos do tronco constituem um desafio reconstrutivo e o tratamento conservador frequentemente não apresenta sucesso. Os retalhos perfurantes são uma solução cada vez mais utilizada para este problema. O retalho perfurante em ilha "Keystone" (RPIK) é um retalho fasciocutâneo de avanço, baseado em vasos perfurantes de localização conhecida, cuja disseção e exposição não é necessária. É desenhado na forma de um trapézio curvilíneo, permitindo o encerramento primário de grandes defeitos, evitando defeitos secundários e minimizando a necessidade de retalhos pediculados tecnicamente mais exigentes, ou métodos de reconstrução microcirúrgica. É apresentado o caso clínico de um homem de 52 anos de idade com doença coronária estável e estenose aórtica severa, com depressão severa da função ventricular esquerda, que foi submetido a cirurgia de revascularização do miocárdio e substituição da válvula aórtica. No período pós-operatório, desenvolveu mediastinite anterior e deiscência da ferida de esternotomia mediana, refratária a tratamento médico e re-intervenções cirúrgicas com desbridamento. O doente foi submetido a reconstrução do defeito com RPIK bilateral e colocação de vacuoterapia, com evolução clínica favorável. O RPIK é uma técnica reconstrutiva que demonstrou utilidade e fiabilidade na abordagem de defeitos complexos, demonstrando tempos operatórios mais curtos, menor risco de necrose total do retalho, escassa morbilidade da zona dadora e resultado estético favorável, tornando-a uma boa opção em pacientes com múltiplas comorbilidades.

Giant Ruptured Common Iliac Artery Infected Aneurysm.

INTRODUCTION: Saccular mycotic aorto-iliac aneurysms are extremely rare and when presented with ruptured, they are an important life- threatening condition. METHODS: We present a 52 years old male transferred from another Hospital and admitted to the emergency room with a ruptured iliac artery aneurysm. RESULTS: He complained of persistent fever and abdominal discomfort that swiftly established as hemorrhagic shock. Imagiological study with angioCT revealed a ruptured left common iliac artery saccular aneurysm with 90mm. The patient was instantaneously and successfully submitted to endoaneurismorraphy, common and external iliac artery ligation and construction of an extra anatomic bypass, right to left femoro-femoral bypass. Blood culture revealed a Streptococcus anginosus and the patient received appropriate targeted antibiotics. Post-operative period was uneventful and the patient discharged ten days after admission. He has now eleven months of follow up with no intercurrences. CONCLUSION: Long term antibiotics along with aggressive surgical debridement of the infected tissue and vascular revascularization with an extra anatomic bypass remain the most definitive solution while endovascular aneurysm repair may generally constitute a bridge life-saving procedure in mycotic infected aneurysms. Even though surgical approach carries a relative risk of perioperative morbidity it is a feasible and durable solution for extreme situations like the one here described.

Pristine Ta3 N5 Nanotubes: Trap-Driven High External Biasing Perspective in Semiconductor/Electrolyte Interfaces.

Ta3 N5 is a promising photoelectrode for solar hydrogen production; however, to date pristine Ta3 N5 electrodes without loading co-catalysts have presented limited photoelectrochemical (PEC) performance. In particular, large external biasing has been required to run water oxidation, the origin of which is investigated herein. Ta3 N5 nanotubes (NTs) prepared by nitridation were characterized by a wide range of techniques. The bandgap was confirmed by a novel PEC technique. Nondestructive synchrotron-excited XPS has shown the presence of reduced Ta species deeper in the Ta3 N5 surface. Lower photocurrent and transient spikes that were intense at lower applied biasing were observed under water oxidation; however, spikes were inhibited in the presence of a sacrificial agent and photocurrent was improved even at low biasing. It was observed for the first time that the lower PEC performance under water oxidation can be attributed to the presence of interband trapping states associated with pristine Ta3 N5 NTs/electrolyte junction. These states correspond to the structural defects in Ta3 N5 , devastate PEC performance, and present the necessity to apply higher biasing. The key to circumvent them is to use a sacrificial agent in the electrolyte or to load a suitable co-catalyst to avoid hole accumulation under water oxidation, thereby improving the phootocurrent. The findings on the interband states could also provide guidance for the investigation of PEC properties of new types of semiconducting devices.

Synthesis and Characterisation of Fluorescent Carbon Nanodots Produced in Ionic Liquids by Laser Ablation.

Carbon nanodots (C-dots) with an average size of 1.5 and 3.0 nm were produced by laser ablation in different imidazolium ionic liquids (ILs), namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4 ), 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf2 ) and 1-n-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (OMI.NTf2 ). The mean size of the nanoparticles is influenced by the imidazolium alkyl side chain but not by the nature of the anion. However, by varying the anion (BF4 vs. NTf2 ) it was possible to detect a significant modification of the fluorescence properties. The C-dots are much probably stabilised by an electrostatic layer of the IL and this interaction has played an important role with regard to the formation, stabilisation and photoluminescence properties of the nanodots. A tuneable broadband fluorescence emission from the colloidal suspension was observed under ultraviolet/visible excitation with fluorescence lifetimes fitted by a multi-exponential decay with average values around 7 ns.

Food and pathogen adaptations in the Angolan Namib desert: Tracing the spread of lactase persistence and human African trypanosomiasis resistance into southwestern Africa.

OBJECTIVES: We investigated the frequency distribution and haplotype diversity of human African trypanosomiasis (HAT) resistance and lactase persistence (LP) variants in populations from the Angolan Namib to trace the spread of these genetic adaptations into southwestern Africa. MATERIALS AND METHODS: We resequenced two fragments of the LCT enhancer and the APOL1 gene and genotyped flanking short tandem repeat loci in six groups with different subsistence traditions living in the Angolan Namib, and in a comparative dataset including other populations from Africa and Europe. LP in the Angolan Namib is represented by the -14010*C allele, which is associated with a predominant haplotype that is shared with other southern and eastern African populations. While LP was found to be more frequent in foragers than in pastoralists, the frequencies of the two APOL1 variants associated with HAT-resistance (G1 and G2) did not differ between the two groups. The G1 allele is mostly associated with a single widespread haplotype. The G2 allele is linked to several haplotypes that are molecularly related to haplotypes found in other African Bantu-speaking populations. The putatively archaic G3 variant displayed more intra-allelic diversity in Africa than in Europe. DISCUSSION: The LP adaptation was carried to southern Africa by non-Bantu speaking pastoralists from eastern Africa, but an obvious link between its presence in southern Angola and groups speaking languages of the Khoe-Kwadi family, as previously found in other areas, could not be confirmed. The presence of APOL1 variants G1 and G2 is linked to the Bantu expansions. Our results suggest that the G3 variant was retained in modern humans by incomplete lineage sorting.