Cristian Munteanu

Mr. Cristian Munteanu

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 October 2023
Verified
Conference Paper
Open access
CMCristian Munteanu
Cristian Munteanu
SSSaid Jawad Saidi
Said Jawad Saidi
OGOliver Gasser
Oliver Gasser
GSGeorgios Smaragdakis
Georgios Smaragdakis
AFAnja Feldmann
Anja Feldmann
Honeypots have been used for decades to detect, monitor, and understand attempts of unauthorized use of information systems. Previous studies focused on characterizing the spread of malware, e.g., Mirai and other attacks, or proposed stealthy and interactive architectures to improve honeypot efficiency. In this paper, we present insights and benefits gained from collaborating with an operational honeyfarm, i.e., a set of honeypots distributed around the globe with centralized data collection. We analyze data of about 400 million sessions over a 15-month period, gathered from a globally distributed honeyfarm consisting of 221 honeypots deployed in 55 countries. Our analysis unveils stark differences among the activity seen by the honeypots-some are contacted millions of times while others only observe a few thousand sessions. We also analyze the behavior of scouters and intruders of these honeypots. Again, some honeypots report orders of magnitude more interactions with command execution than others. Still, diversity is needed since even if we focus on the honeypots with the highest visibility, they see only a small fraction of the intrusions, including only 5% of the files. Thus, although around 2% of intrusions are visible by most of the honeypots in our honeyfarm, the rest are only visible to a few. We conclude with a discussion of the findings of work.

30 August 2024 in Microorganisms
Verified
Journal Article
Open access
PDF file
YDYaser Abu Dail
Yaser Abu Dail
EFElias Flockerzi
Elias Flockerzi
CMCristian Munteanu
Cristian Munteanu
NSNora Szentmary
Nora Szentmary
Berthold SeitzBerthold Seitz
Berthold Seitz
LDLoay Daas
Loay Daas
Background: Early therapeutic penetrating keratoplasty (TKP) for Acanthamoeba keratitis (AK) is thought to have a worse visual prognosis than the delayed optical penetrating keratoplasty (OKP) after successful conservative treatment of AK. This has led to a tendency to prolong conservative therapy and delay penetrating keratoplasty in patients with AK. This retrospective series presents the results of patients with AK that underwent early penetrating keratoplasty after reducing the corneal amoeba load through intensive conservative therapy, so-called “low load keratoplasty” (LLKP). Patients and methods: The medical records of our department were screened for patients with AK, confirmed by histological examination and/or PCR and/or in vivo confocal microscopy, which underwent ab LLKP and had a follow-up time of at least one year between 2009 and 2023. Demographic data, best corrected visual acuity (BCVA) and intraocular pressure at first and last visit, secondary glaucoma (SG), and recurrence and graft survival rates were assessed. Results: 28 eyes of 28 patients were included. The average time from initiation of therapy to penetrating keratoplasty (PKP) was 68 ± 113 days. The mean follow-up time after LLKP was 53 ± 42 months. BCVA (logMAR) improved from 1.9 ± 1 pre-operatively to 0.5 ± 0.6 at last visit (p < 0.001). A total of 14% of patients were under medical therapy for SG at the last visit, and two of them underwent glaucoma surgery. The recurrence rate was 4%. The Kaplan–Meier graft survival rate of the first graft at four years was 70%. The second graft survival rate at four years was 87.5%. Conclusion: LLKP appears to achieve a good visual prognosis with an earlier visual and psychological habilitation, as well as low recurrence and SG rates. These results should encourage us to reconsider the optimal timing of PKP in therapy-resistant AK.

19 January 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
ESEmilia Sophie Stuhlmacher
Emilia Sophie Stuhlmacher
SSShady Suffo
Shady Suffo
CMCristian Munteanu
Cristian Munteanu
Berthold SeitzBerthold Seitz
Berthold Seitz
LDLoay Daas
Loay Daas
Purpose: Evaluating the learning curve of individual surgeons for Descemet Membrane Endothelial Keratoplasty (DMEK) and Triple-DMEK and assessing outcome with experience. Methods: The first 41 and the last 41 surgeries of each of the four surgeons were retrospectively included. Surgery duration and graft preparation time were recorded. Corrected distance visual acuity (CDVA, logMAR) and central corneal thickness (CCT, µm) were collected preoperatively after 6 and 12 months, as well as postoperative complications, e.g., re-bubbling or repeat penetrating keratoplasty. Results: Surgical duration for Triple-DMEK and DMEK decreased significantly by 21 min and 14 min between the two periods (p < 0.001; p < 0.001). Graft preparation time decreased significantly from 13.3 ± 5.2 min (95%CI 12.8–14.3) in period 1 to 10.7 ± 4.8 min (95%CI 10.2–11.4) in period 2 (p = 0.002). The postoperative changes in CDVA and CCT over both periods were not significant (p = 0.900; p = 0.263). The re-bubbling rate decreased significantly from 51.2% in period 1 to 26.2% in period 2 (p < 0.001). The repeat penetrating keratoplasty (PKP) was 7.3% in period 1 and 3.7% in period 2 (p = 0.146). Re-DMEK was necessary in 6.1% in period 1 and 4.9% in period 2 (p = 0.535). Several parameters showed significant differences between the surgeons in both periods (surgical duration: period 1: p < 0.001, period 2 p < 0.001; graft preparation: period 1: p < 0.001, period 2 p < 0.001). Conclusion: Significant decrease in surgery duration, graft preparation time, and the re-bubbling rate can be attributed to gained individual experience.

17 December 2024 in Current Eye Research
Verified
Journal Article
Closed access
ANAnnamária Náray
Annamária Náray
Fabian Norbert FriesFabian Norbert Fries
Fabian Norbert Fries
CMCristian Munteanu
Cristian Munteanu
MCMária Csidey
Mária Csidey
TSTanja Stachon
Tanja Stachon
NSNora Szentmary
Nora Szentmary
The potential risks and benefits of cataract surgery, in context of congenital aniridia (CA), are not widely understood, yet. Our purpose was to investigate the effect of lens properties on visual acuity (VA), aniridia-associated keratopathy (AAK) stage and presence of glaucoma at the Homburg Aniridia Center. CA subjects, examined at the Department of Ophthalmology of Saarland University between June 2003 and January 2022, were included. VA, slit-lamp examination, AAK grade, and glaucoma evaluation data were extracted from the medical records, from the first visit to the center. Eyes were categorized as clear lens, cataract, pseudophakic, aphakic, or subluxated lens. Patients were grouped by age (0-10, 10-20, 20-40, 40+ years). In 553 eyes of 286 CA subjects (age 19.9 ± 19.9 (0-83) years, 46.1% males), analysis revealed significant differences in VA and mean IOP (ANOVA p < 0.0001; p = 0.001, respectively) with lens status. Lens status was strongly associated with AAK Grade and glaucoma presence (p < 0.0001 for both). In age subgroups, AAK Stage was strongly associated with lens status in the 0-10 years (p < 0.001), 10-20 years (p < 0.001), and 40+ years (p = 0.02) groups and lens status was strongly associated with glaucoma presence in the 0-10 years (p = 0.003) and 20-40 years (p = 0.002) groups. AAK Stage was the most advanced in pseudophakic and aphakic eyes and presence of glaucoma was more pronounced in pseudophakic, aphakic and subluxated lens eyes. In a large population of CA, previous cataract surgery was associated with higher AAK Grade and presence of secondary glaucoma both in postoperatively pseudophakic and aphakic eyes. Our data indicate that caution is warranted with cataract surgery in congenital aniridia.

1 March 2025 in Cornea
Verified
Journal Article
Closed access
LDLoay Daas
Loay Daas
WAWissam Aljundi
Wissam Aljundi
AAAlaa Din Abdin
Alaa Din Abdin
CMCristian Munteanu
Cristian Munteanu
BSBerthold MD Seitz
Berthold MD Seitz
Purpose: To evaluate the outcome of excimer laser-assisted deep anterior lamellar keratoplasty (Exc-DALK) and penetrating keratoplasty (Exc-PKP) for keratoconus (KC). Methods: We included 123 eyes and compared the outcome of 30 eyes undergoing big-bubble Exc-DALK after stromal debulking (G1) against a matched group of 83 eyes undergoing Exc-PKP (G2) in our department. G2 was created after performing a pseudorandom stratified bootstrapping of our PKP database starting with 2802 surgeries with removal of any bias. Main outcomes included best corrected visual acuity (BCVA), spherical equivalent (SE), tomographic changes, and endothelial cell density (ECD). Data were compared preoperatively, postoperatively with 2 double-running cross-stitch sutures according to Hoffmann [2 and 10 months postoperatively (T1 and T2)], after first suture removal [15 months postoperatively (T3)], and after final suture removal [26 months postoperatively (T4)]. Results: Preoperatively, all parameters were comparable without significant differences. At T1, G1 showed significantly better BCVA (P = 0.01), lower SE (P = 0.04), lower anterior and posterior topographic astigmatism (ATA and PTA, P < 0.01), lower maximal keratometry (P = 0.02), and lower central corneal thickness (P < 0.01). At T2, G1 showed significantly better BCVA (P = 0.04), lower PTA (P < 0.01), and higher ECD (P < 0.01). At T3, G1 showed significantly lower ATA (P = 0.01) and PTA (P < 0.01) and higher ECD (P = 0.02). At T4, G1 showed significantly lower PTA and higher ECD (P < 0.01) but no significant difference in BCVA (P = 0.07). Conclusions: Exc-DALK provided faster visual rehabilitation and represented an endothelial cell-sparing method compared with Exc-PKP. After final suture removal, Exc-DALK showed noninferior outcomes compared with Exc-PKP if the graft was placed on naked Descemet membrane.

22 July 2023
Verified
Conference Paper
Open access
CMCristian Munteanu
Cristian Munteanu
OGOliver Gasser
Oliver Gasser
IPIngmar Poese
Ingmar Poese
GSGeorgios Smaragdakis
Georgios Smaragdakis
AFAnja Feldmann
Anja Feldmann
Today, there is an increasing number of peering agreements between Hypergiants and networks that benefit millions of end-user. However, the majority of Autonomous Systems do not currently enjoy the benefit of interconnecting directly with Hypergiants to optimally select the path for delivering Hypergiant traffic to their users. In this paper, we develop and evaluate an architecture that can help this long tail of networks. With our proposed architecture, a network establishes an out-of-band communication channel with Hypergiants that can be two or more AS hops away and, optionally, with the transit provider. This channel enables the exchange of network information to better assign requests of end-users to appropriate Hypergiant servers. Our analysis using operational data shows that our architecture can optimize, on average, 15% of Hypergiants' traffic and 11% of the overall traffic of networks that do not interconnect with Hypergiants. The gains are even higher during peak hours when available capacity can be scarce, up to 46% for some Hypergiants.