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1.
Niger J Clin Pract ; 27(4): 430-434, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38679763

ABSTRACT

BACKGROUND: Various types of nasal tampons are used for packing after septoplasty. Intranasal splints are widely used as they are more advantageous than other materials regarding the lower complication rates of synechia, and lesser pain during removal. However, there is no consensus on the timing of intranasal splint removal after septoplasty operations. AIM: In this study, we aimed to investigate the effects of removal time of intranasal splints on postoperative complications after septoplasty. METHODS: One hundred patients who had septoplasty were randomly divided into two groups according to splint removal time. In group I, the splints were removed on the third postoperative day and in group II, splints were removed on the seventh postoperative day. Pain during splint removal was evaluated by visual analog scale (VAS). Complications of hemorrhage, septal hematoma, crusting, mucosal injury, and infection were recorded during splint removal and compared. In the first postoperative month, hemorrhage, crusting, mucosal injury, infection, synechia, and in the second postoperative month, synechia and perforation rates were compared between two groups. RESULTS: Mucosal crusting was significantly higher in group II during splint removal. There was no statistically significant difference between the two groups regarding the complication rates and pain scores. Our findings showed no significant difference in pain scores during splint removal and postoperative complications between the two groups except for mucosal crusting. CONCLUSION: Based on our findings, although there is no consensus on the optimal time for splint removal, earlier removal of splints can be considered a favorable option after septoplasty operations.


Subject(s)
Nasal Septum , Postoperative Complications , Splints , Humans , Female , Male , Adult , Nasal Septum/surgery , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Rhinoplasty/adverse effects , Rhinoplasty/methods , Time Factors , Middle Aged , Young Adult , Tampons, Surgical , Device Removal , Pain, Postoperative/etiology , Pain, Postoperative/epidemiology , Adolescent , Pain Measurement
2.
Eur Rev Med Pharmacol Sci ; 28(4): 1366-1374, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38436169

ABSTRACT

OBJECTIVE: This study aimed to evaluate the effects of affected knee flexion for 24 vs. 72 hours on blood loss, pain, range of motion, and functional outcomes after total knee arthroplasty. PATIENTS AND METHODS: The present study included 46 participants with a mean age of 64.33 ± 6.70 years. The affected knee of the first 23 participants, based on the order of operations, was positioned at 70° flexion for 24 hours, and the knee of the next 23 participants was positioned at 70° flexion for 72 hours. Participants were evaluated before the operation and on postoperative day 3 and week 6. Pain, edema, range of motion, time up and go test scores, and Western Ontario McMaster Universities Arthritis Index scores, hemoglobin, and hematocrit were measured before the operation and on postoperative at day 3 and week 6. RESULTS: We found that the calculated blood loss was 575.07 ± 282.44 and 578.39 ± 297.11 mL in patients who underwent short- and long-duration flexion positioning, respectively (p = 0.921). The active flexion angles at postoperative week 6 were 83.61° ± 22.03° and 105.91° ± 13.06° in the short- and long-duration flexion groups, respectively (p < 0.01). Furthermore, the Western Ontario and McMaster Universities Arthritis Index scores at postoperative week 6 were 35.52 ± 24.71 and 17.17 ± 15.37 in the short- and long-duration flexion groups, respectively (p < 0.01). CONCLUSIONS: Long-duration flexion positioning after total knee arthroplasty may lead to better middle-term flexion range of motion and physical function scores than short-duration flexion positioning.


Subject(s)
Arthritis , Arthroplasty, Replacement, Knee , Humans , Middle Aged , Aged , Postural Balance , Time and Motion Studies , Pain
3.
Science ; 383(6679): 168-173, 2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38207019

ABSTRACT

The short de Broglie wavelength and strong interaction empower free electrons to probe structures and excitations in materials and biomolecules. Recently, electron-photon interactions have enabled new optical manipulation schemes for electron beams. In this work, we demonstrate the interaction of electrons with nonlinear optical states inside a photonic chip-based microresonator. Optical parametric processes give rise to spatiotemporal pattern formation corresponding to coherent or incoherent optical frequency combs. We couple such "microcombs" to electron beams, demonstrate their fingerprints in the electron spectra, and achieve ultrafast temporal gating of the electron beam. Our work demonstrates the ability to access solitons inside an electron microscope and extends the use of microcombs to spatiotemporal control of electrons for imaging and spectroscopy.

4.
Eur Rev Med Pharmacol Sci ; 27(22): 10944-10950, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38039024

ABSTRACT

OBJECTIVE: Depression affects adolescents worldwide and often predicts more serious disease manifestations in later lifetimes. Peer victimization or bullying, another form of child abuse, increases symptoms of depression. In this paper, the relationship between peer bullying and depression in adolescence was investigated. SUBJECTS AND METHODS: Each adolescent who was admitted to the adolescent unit completed forms referred to as the 'Depression Scale For Children' and the 'Multidimensional Peer Victimization Scale'. Sociodemographic features and results of the scales' evaluation were studied. SPSS 16.0 program was used for statistical analysis. The p-value below 0.05 was considered statistically significant. RESULTS: 239 adolescents, 120 of whom were male, were investigated. A positive relationship was determined among total and sub-scale scores of peer victimization-determining scale and depression scale scores. A negative relationship was determined between height, weight, age of the child, and sub-scale score of threat/intimidation. Both the total score of the peer victimization-determining scale and sub-scale scores of ridicule, open attack, and relational attack pertaining to patients with depression proved to be significantly higher than in those without depression. CONCLUSIONS: The awareness of educators and parents, notably adolescents, must be raised in regard to peer victimization, and activities for increasing the communicative skills of adolescents and for allowing them to be able to express their emotions should also be performed. Identifying and preventing peer victimization, one of the causes of depression, and launching the treatment process for this are the first steps to be taken in terms of a healthy adulthood.


Subject(s)
Bullying , Crime Victims , Child , Humans , Male , Adolescent , Adult , Female , Depression/psychology , Emotions , Peer Group , Bullying/psychology , Crime Victims/psychology
5.
Eur Rev Med Pharmacol Sci ; 27(21): 10446-10453, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37975368

ABSTRACT

OBJECTIVE: The present research aimed to study the possible protective effects of Silymarin on testicular I/R injury in a rat model evaluated through histopathology and biochemical parameters. MATERIALS AND METHODS: This research investigated the impact of Silymarin on IR damage in male Wistar albino rats. Animals were divided into three groups: group 1 (sham), group 2 (IR), and group 3 (IR+Silymarin). RESULTS: There were no notable differences in the levels of malondialdehyde (MDA), myeloperoxidase (MPO), and glutathione (GSH) across the three groups (p=0.260, p=0.486 and p=0.803, respectively). Contrarily, the total antioxidant status (TAS) levels exhibited significant variations between groups (p=0.001). The total oxidant status (TOS) levels also differed significantly between groups (p=0.004). The tissue evaluations uncovered substantial differences in the Johnson score, which is used to gauge testicular damage. A distinct contrast was seen between Group 1 and Group 2, and also between Group 2 and Group 3, with an all-encompassing p-value lower than 0.01. The same significant disparities were found for the percentages of Bax and Annexin V immunostaining (p<0.01 for each), reflecting the inflammation and apoptosis brought about by ischemia-reperfusion and the protective effects of the treatment. CONCLUSIONS: The outcomes of the current investigation showed that Silymarin could be a valuable agent for reducing testicular tissue damage following I/R injury.


Subject(s)
Reperfusion Injury , Silymarin , Spermatic Cord Torsion , Humans , Rats , Male , Animals , Spermatic Cord Torsion/drug therapy , Spermatic Cord Torsion/metabolism , Spermatic Cord Torsion/pathology , Rats, Wistar , Silymarin/pharmacology , Oxidative Stress , Reperfusion Injury/metabolism , Testis , Antioxidants/pharmacology , Antioxidants/metabolism , Glutathione/metabolism , Malondialdehyde/metabolism
6.
J Endocrinol Invest ; 46(11): 2411-2420, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37704872

ABSTRACT

OBJECTIVE: This study aimed to investigate the relationship between hypercortisolism and temporal muscle thickness (TMT) in Cushing's disease (CD). METHODS: A retrospective review of medical records was conducted for patients with CD who presented to our clinic between 2012 and 2022. Biochemical data and TMT measurements from sella imaging were evaluated during diagnosis and the first postoperative year. RESULTS: A total of 44 patients were included in the study, with an average age of 43.9 years, of which 38 were female. The mean TMT at the time of diagnosis was 19.07 ± 1.71 mm, with no significant difference between males and females (p = 0.097), and no correlation between the TMT and age at diagnosis (p = 0.497). There was an inverse relationship between TMT and serum cortisol levels, 24-h UFC, and midnight salivary cortisol at the time of diagnosis of CD (p < 0.05, for all). One year after surgery, TMT significantly increased in all patients compared to baseline (p < 0.001). Furthermore, patients who achieved postoperative remission had significantly higher TMT values compared to those who did not achieve remission (p = 0.043). Among the patients who achieved remission, those who achieved remission through surgery had significantly higher TMT compared to those who could not reach remission with surgery and patients who started medical treatment and achieved biochemical remission (p = 0.01). Patients with severe myopathy and sarcopenia had significantly lower TMT values than the others (p < 0.001). CONCLUSION: Temporal muscle thickness was found to be associated with disease activity and disease control in Cushing's disease.

9.
Niger J Clin Pract ; 26(7): 921-927, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37635575

ABSTRACT

Background: Type 1 fascia graft tympanoplasty (T1FGT) is the mainstay surgical approach for the treatment of tympanic membrane perforations. The most widely used graft material is temporal muscle fascia, and graft take rates are reported differently. The methods to enhance graft take are still being investigated. Aim: The aim of our study was to investigate the effect of titanium-prepared platelet-rich fibrin (T-PRF) on graft take and hearing outcomes in T1FGT. Materials and Methods: Fifty-seven ears eligible for T1FGT were involved in the study and prospectively evaluated. T-PRF was applied with T1FGT in 27 ears. Thirty ears in the other group underwent only T1FGT. The patients underwent an otomicroscopic and audiometric examination in preoperative and postoperative 2nd week, 1st month, and 6th month. Both groups were evaluated in terms of hearing levels, infection, and graft take rates. Results: Two patients in the T1FGT + T-PRF group and seven patients in the T1FGT group had postoperative perforation (graft take rate: 92.6% versus 76.7%). The graft take rate was found to be increased in the T-PRF group although the difference was not statistically significant. In the T1FGT group, the percentage of infection was higher than in the T1FGT + T-PRF group. When the preoperative and postoperative 6th-month audiometry was compared, a statistically significant hearing gain was obtained for both groups. Conclusion: In the treatment of tympanic membrane perforations, T-PRF applied over the fascia graft was shown to increase graft take rates and decrease the probability of infection. Further studies with larger samples are needed to demonstrate the effects of PRF.


Subject(s)
Platelet-Rich Fibrin , Tympanic Membrane Perforation , Humans , Titanium , Graft Survival , Tympanoplasty , Hearing , Tympanic Membrane Perforation/surgery , Fascia
10.
Niger J Clin Pract ; 25(9): 1517-1522, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36149213

ABSTRACT

Background: Morgagni hernia (MH) is a rare congenital defect of the diaphragm. Although the various surgical method has been proposed, there is no surgical consensus. Aim: In this study, we aimed to report the outcome of the patients that underwent surgery which is completed using a single port laparoscopic-assisted transabdominal closure of MH. Patients and Methods: This is a retrospective analysis of 18 pediatric patients who underwent novel laparoscopic MH repair at a single tertiary pediatric hospital between March 2018 and December 2020. Results: Of the 18 patients, 72% (n = 13) were male and 28% (n = 5) were female. The symptoms at admission included repeated chest infection (39%), dyspnea (33%), vomiting (17%), and abdominal pain (22%). The colon (78%) was the most frequently herniated organ. Hernias were bilateral, on the left, and on the right in seven, four, and seven cases, respectively. All surgical interventions were completed within 25-50 min. All patients started enteral feeding within 24 hours. All patients were discharged within 1-3 days without any complications. The mean follow-up period was 27 months. Conclusions: In conclusion, our method is characterized by a shorter operation time, early return to feeding, early discharge, excellent cosmetic results, low cost, and low recurrence rate. Further prospective trials are needed to compare our novel scarless technique to other methods.


Subject(s)
Hernias, Diaphragmatic, Congenital , Laparoscopy , Child , Female , Hernias, Diaphragmatic, Congenital/diagnosis , Hernias, Diaphragmatic, Congenital/surgery , Herniorrhaphy/methods , Humans , Laparoscopy/methods , Male , Patient Discharge , Retrospective Studies
12.
Rev Sci Instrum ; 93(6): 063902, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35778005

ABSTRACT

We introduce a simple method to extract the nuclear coherent and isotope incoherent, spin incoherent, and magnetic neutron scattering cross section components from powder scattering data measured using a single neutron beam polarization direction and a position-sensitive detector with large out-of-plane coverage. The method draws inspiration from polarized small-angle neutron scattering and contrasts with conventional so-called "xyz" polarization analysis on wide-angle instruments, which requires measurements with three orthogonal polarization directions. The viability of the method is demonstrated on both simulated and experimental data for the classical "spin ice" system Ho2Ti2O7, the latter from the LET direct geometry spectrometer at the ISIS facility. The cross section components can be reproduced with good fidelity by either fitting the out-of-plane angle dependence around a Debye-Scherrer cone or grouping the data by angle and performing a matrix inversion. The limitations of the method and its practical uses are discussed.

13.
J Mycol Med ; 32(2): 101245, 2022 May.
Article in English | MEDLINE | ID: mdl-35063761

ABSTRACT

Aspergillosis is a rare and life-threatening fungal infection in immunocompetent children, particularly in infants. We present a case of invasive Aspergillosis (IA) that developed hepatic and mesh infection due to Aspergillus flavus following the rupture of a giant omphalocele. A male baby was born at 37 weeks of gestation with a giant omphalocele. No other congenital abnormalities were found. In the pediatric surgery operation room, the amniotic membrane seemed to be ruptured in some parts, which had been repaired within a few hours of birth. No further intervention to reduce the volume of visceral organs could be performed due to the tiny abdominal cavity. Postoperatively piperacillin-tazobactam and fluconazole were empirically initiated. Abdominal defects had been covered with polypropylene polylactic acid synthetic Mesh on postnatal day 11 to protect the organs and prevent abdominal infections. Fungal hepatic lesions were observed during surgery, and black necrotic lesions were also observed on the mesh on day 12. On the 16th postnatal day, Aspergillus flavus grew in the wound, graft, hepatic biopsy cultures. Serum galactomannan (GM) assay test was positive (GM:2.9), and voriconazole was initiated. All necrotic lesions resolved with liposomal amphotericin B (L-AmB) and voriconazole treatment, and antifungal therapy was discontinued after 134 days. Eye examination for the retinopathy didn't show any abnormalities. The patient was discharged with full recovery on day 155. In conclusion, IA is a rare and life-threatening infection in the neonatal period. To the best of our knowledge, this is the first case of hepatic and mesh infection caused by Aspergillus flavus that was successfully treated with voriconazole and l-AmB.


Subject(s)
Aspergillosis , Hernia, Umbilical , Invasive Fungal Infections , Antifungal Agents/therapeutic use , Aspergillosis/diagnosis , Aspergillosis/drug therapy , Aspergillosis/etiology , Aspergillus flavus , Child , Hernia, Umbilical/complications , Hernia, Umbilical/drug therapy , Humans , Infant, Newborn , Invasive Fungal Infections/drug therapy , Male , Surgical Mesh/adverse effects , Voriconazole
14.
Acta Endocrinol (Buchar) ; 18(3): 278-287, 2022.
Article in English | MEDLINE | ID: mdl-36699179

ABSTRACT

Aim: Diabetic macular oedema (DME) can develop at all stages of diabetic retinopathy, causing visual impairment and blindness. Modern diets are high in advanced glycation end products (dAGEs), derived from processing methods, exerting a pivotal role in promoting diabetic retinopathy risk. In present study, we investigate the relationship between dietary and serum levels of AGEs and DME in type 2 diabetic subjects. Methods: This case-control study was conducted between July 2018 and February 2019 on 50 case subjects with DME and 40 healthy controls without DM without DME. The sociodemographic characteristics, nutritional status, and anthropometric measurements were evaluated. The advanced glycation end products (AGEs) and receptor for AGEs (sRAGE) levels in serum were analysed. Results: The AGEs levels of the DME group were higher than in the control group (p <0.05). sRAGE levels were higher in the DME group, but not statistically significant (p >0.05). The dietary intake of AGEs was higher in the DME group (p <0.05). It was found that an increase in neck circumference increased the risk of DME (p <0.001). Conclusion: A positive correlation was found between DME and AGEs, dAGE, neck circumference, and waist circumference. For the validity of these results, studies, including controlled nutrition interventions, are needed.

15.
Nat Commun ; 12(1): 2236, 2021 Apr 16.
Article in English | MEDLINE | ID: mdl-33863901

ABSTRACT

Low-loss photonic integrated circuits and microresonators have enabled a wide range of applications, such as narrow-linewidth lasers and chip-scale frequency combs. To translate these into a widespread technology, attaining ultralow optical losses with established foundry manufacturing is critical. Recent advances in integrated Si3N4 photonics have shown that ultralow-loss, dispersion-engineered microresonators with quality factors Q > 10 × 106 can be attained at die-level throughput. Yet, current fabrication techniques do not have sufficiently high yield and performance for existing and emerging applications, such as integrated travelling-wave parametric amplifiers that require meter-long photonic circuits. Here we demonstrate a fabrication technology that meets all requirements on wafer-level yield, performance and length scale. Photonic microresonators with a mean Q factor exceeding 30 × 106, corresponding to 1.0 dB m-1 optical loss, are obtained over full 4-inch wafers, as determined from a statistical analysis of tens of thousands of optical resonances, and confirmed via cavity ringdown with 19 ns photon storage time. The process operates over large areas with high yield, enabling 1-meter-long spiral waveguides with 2.4 dB m-1 loss in dies of only 5 × 5 mm2 size. Using a response measurement self-calibrated via the Kerr nonlinearity, we reveal that the intrinsic absorption-limited Q factor of our Si3N4 microresonators can exceed 2 × 108. This absorption loss is sufficiently low such that the Kerr nonlinearity dominates the microresonator's response even in the audio frequency band. Transferring this Si3N4 technology to commercial foundries can significantly improve the performance and capabilities of integrated photonics.

16.
Nano Lett ; 21(7): 2709-2718, 2021 Apr 14.
Article in English | MEDLINE | ID: mdl-33754742

ABSTRACT

Monolayer transition-metal dichalcogenides with direct bandgaps are emerging candidates for optoelectronic devices, such as photodetectors, light-emitting diodes, and electro-optic modulators. Here we report a low-loss integrated platform incorporating molybdenum ditelluride monolayers with silicon nitride photonic microresonators. We achieve microresonator quality factors >3 × 106 in the telecommunication O- to E-bands. This paves the way for low-loss, hybrid photonic integrated circuits with layered semiconductors, not requiring heterogeneous wafer bonding.

17.
Acta Endocrinol (Buchar) ; 17(3): 358-364, 2021.
Article in English | MEDLINE | ID: mdl-35342481

ABSTRACT

Context: The prevalence of both heart failure and vitamin D deficiency increases with age and is associated with poor outcome in the elderly. Objectives: We aimed to investigate the relationship between all-cause mortality and vitamin D deficiency in elderly patients with chronic heart failure. Design: It is a retrospective, observational cross-sectional study. Median follow-up time was 497 days. Subjects and Methods: 302 patients aged ≥65 years heart failure patients was categorized into tertiles based on the 25-hydroxy-vitamin D levels. Clinical and laboratory parameters were evaluated according to tertiles. Hospitalization rates and overall survival were compared between tertiles. Independent predictors of all cause mortality were defined. Results: Patients with low vitamin D tertile were mostly women (p=0.001), and had a worse NYHA functional class (p=0.005). During follow-up, deaths were more frequent in the first tertile (p = 0.001). All-cause mortality increased significantly with decreasing vitamin D tertiles (from third tertile 7.9%, to 11.9%, to 26%; log rank test p=0.003). No significant difference was observed at the composite endpoint of mortality or HF hospitalizations (P=0.451). Multivariate analysis supported that low vitamin D concentration was an independent predictor of all causes of mortality (HR 0.93; 95% CI 0.89-0.97; p=0.004). Conclusions: Low vitamin D levels were independent predictors of all-cause mortality in the elderly population with chronic heart failure.

18.
Niger J Clin Pract ; 23(12): 1683-1689, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33355821

ABSTRACT

OBJECTIVES: The study aims to retrospectively review the survival and toxicity outcomes of adaptive helical tomotherapy (HT) treatment of nasopharyngeal carcinoma (NPC) patients over 5 years. METHODS: Between February 2010 and September 2017, 67 biopsy-proven non-metastatic NPC patients were analyzed. All patients except one received concurrent chemotherapy and treated with adaptive Simultaneous integrated boost- intensity-modulated radiation therapy (SIB-IMRT). The median age was 48.5 years (range, min: 11 max: 78) with male predominance (82.1% vs. 17.9%). Neck mass was the most common presenting symptom followed by hearing problems (52% and 24%). RESULTS: The mean dose with standard deviation (sd) of D50 to patients' parotid glands and cochleae were 33 ± 11 Gy; 31 ± 11 9 Gy and 37 ± 11 14 Gy; 34 ± 11 14 Gy, respectively. Locoregional progression-free survival (LRRFS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and overall survival (OS) estimated at 2 and 5 years were 83% and 63%, 78.4% and 61.7%, 83% and 69%, 86% and 71%, respectively. Acute Grade 3 or higher dysphagia and mucositis observed in 28 (42%) patients who required daily iv fluid transfusion and/or hyperalimentation. None of the patients had grade 3 and higher mucous membranes and salivary gland toxicity beyond 6 months. Two patients had ≥ grade 3 late toxicity. During the median 51 months (range 2-100) follow up, thirteen patients relapsed (19.4%), six of them (8.9%) recurred locoregionally, and 7 (10.4%) of them developed distant metastasis. CONCLUSION: The present study reemphasizes that adaptive SIB-IMRT with HT is a good option for the management of NPC with comparable loco-regional control rates and low salivary gland toxicity.


Subject(s)
Nasopharyngeal Neoplasms , Radiotherapy, Intensity-Modulated , Child , Humans , Male , Nasopharyngeal Carcinoma/radiotherapy , Nasopharyngeal Neoplasms/radiotherapy , Neoplasm Recurrence, Local , Radiotherapy, Intensity-Modulated/adverse effects , Retrospective Studies , Treatment Outcome
19.
Nat Commun ; 11(1): 4377, 2020 Sep 01.
Article in English | MEDLINE | ID: mdl-32873798

ABSTRACT

The rapidly maturing integrated Kerr microcombs show significant potential for microwave photonics. Yet, state-of-the-art microcomb-based radiofrequency filters have required programmable pulse shapers, which inevitably increase the system cost, footprint, and complexity. Here, by leveraging the smooth spectral envelope of single solitons, we demonstrate microcomb-based radiofrequency filters free from any additional pulse shaping. More importantly, we achieve all-optical reconfiguration of the radiofrequency filters by exploiting the intrinsically rich soliton configurations. Specifically, we harness the perfect soliton crystals to multiply the comb spacing thereby dividing the filter passband frequencies. Also, the versatile spectral interference patterns of two solitons enable wide reconfigurability of filter passband frequencies, according to their relative azimuthal angles within the round-trip. The proposed schemes demand neither an interferometric setup nor another pulse shaper for filter reconfiguration, providing a simplified synthesis of widely reconfigurable microcomb-based radiofrequency filters.

20.
Nature ; 583(7816): 385-390, 2020 07.
Article in English | MEDLINE | ID: mdl-32669694

ABSTRACT

High-speed actuation of laser frequency1 is critical in applications using lasers and frequency combs2,3, and is a prerequisite for phase locking, frequency stabilization and stability transfer among optical carriers. For example, high-bandwidth feedback control of frequency combs is used in optical-frequency synthesis4, frequency division5 and optical clocks6. Soliton microcombs7,8 have emerged as chip-scale frequency comb sources, and have been used in system-level demonstrations9,10. Yet integrated microcombs using thermal heaters have limited actuation bandwidths11,12 of up to 10 kilohertz. Consequently, megahertz-bandwidth actuation and locking of microcombs have only been achieved with off-chip bulk component modulators. Here we demonstrate high-speed soliton microcomb actuation using integrated piezoelectric components13. By monolithically integrating AlN actuators14 on ultralow-loss Si3N4 photonic circuits15, we demonstrate voltage-controlled soliton initiation, tuning and stabilization with megahertz bandwidth. The AlN actuators use 300 nanowatts of power and feature bidirectional tuning, high linearity and low hysteresis. They exhibit a flat actuation response up to 1 megahertz-substantially exceeding bulk piezo tuning bandwidth-that is extendable to higher frequencies by overcoming coupling to acoustic contour modes of the chip. Via synchronous tuning of the laser and the microresonator, we exploit this ability to frequency-shift the optical comb spectrum (that is, to change the comb's carrier-envelope offset frequency) and make excursions beyond the soliton existence range. This enables a massively parallel frequency-modulated engine16,17 for lidar (light detection and ranging), with increased frequency excursion, lower power and elimination of channel distortions resulting from the soliton Raman self-frequency shift. Moreover, by modulating at a rate matching the frequency of high-overtone bulk acoustic resonances18, resonant build-up of bulk acoustic energy allows a 14-fold reduction of the required driving voltage, making it compatible with CMOS (complementary metal-oxide-semiconductor) electronics. Our approach endows soliton microcombs with integrated, ultralow-power and fast actuation, expanding the repertoire of technological applications of microcombs.

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